We asked three subsamples of students to keep a diary of their drug use over a period of six months. This chapter reports on those diaries, which were set up to include a record of kinds of drug use, incidence, time of use or ingestion, people present, the purpose for taking a drug, the effects experienced, and the events associated with any important changes in regular drug-taking patterns—that is, with innovation or marked reduction in use.

In two schools, I and II, the subsamples selected to keep a drug diary were drawn at random (random-numbers table) from the larger sample constituting our study population at each school. In a third school, IV, panelists were not selected at random from the study population but, instead, were selected because they were found to use illicit-exotic drugs. We selected such a group because we wanted to know more about the day-to-day drug habits of illicit-exotic users as such. In School I we began with thirty-six students and ended up six months later with twenty-two in the panel; School II began with twenty-eight and also ended up with twenty-two. School IV began with thirty-six and at the end had only sixteen, and these for only five months instead of six. Panels in Schools I and II began recording in November of 1966 and completed work in April of 1967. The panel in School IV began in January of 1967 and completed work in May 1967.

To reduce the amount of recording required for students, we developed a modified diary which required that on only seven days each month would a record be kept. To avoid any systematic error due to recording the same week consistently in the month, we rotated the weeks—that is, students began recording with the first week of November, then with the second week of December, the third week of January, and so forth. In case anything special happened with regard to drug usage during any of the off-weeks, students also completed a monthly summary noting any remarkable changes in drug use or in drug effects. We kept in touch with the students during the panel period, encouraging them as best we could with reminders, thanks, pleas, and gifts of pens to keep at it. It was, for some, a tedious job, and we are much in debt to those who persisted.

DRUGS USED

Alcohol. Seventy-two per cent of the students at School I, 71 per cent at School II, and 42 per cent at School IV record having used alcohol on diary days. Results show the most common pattern of drinking to be between one and six times a week. Only one panelist records drinking on fifteen or more occasions within the same week. For the two schools whose panelists represent a subsample of the larger sample and thus have some claim to representativeness (that claim diminished by small sample size), drinking occasions are reported to occur about every four and a half days. In the School IV group with its smaller alcohol intake that average is raised to about once every week.

Not unexpectedly, the most popular time of day for drinking is evenings—at least in Schools I and II; afternoons rank first in School IV. In all schools alcohol consumption at mealtimes ranks second. School I shows five specific occasions of morning drinking, one in School II, and none in School IV. Drinking with close friends is the most prevalent pattern. In School II, the Catholic university, these family drinking occasions are proportionately much more common than in the other schools. Twenty-three occasions of drinking alone are recorded at School I, six at School II, and five at School IV. Compatible with the group setting, most drinking occasions are said to be shared group activities. As far as stating further purpose is possible, students report the most common is to achieve pleasure. On the other hand, on fifteen occasions in School I, fourteen in II, and four in IV, the students say their drinking was to relieve psychological distress.

With regard to marked changes in drinking habits, these are few. Their occurrence—specifically, in six instances—represents innovations in drinking among previous nondrinkers and are attributed in one case to group pressure, in four instances to curiosity, and in another to escape from tension. These same reasons in that same order are offered as explanations of increases in amounts consumed over ordinary practices; such increases are noted on fifty-seven occasions. In contrast, decreases recorded over ordinary drinking habits are indicated on only eleven occasions, most of these also attributable to social pressure. In two cases students gave up drinking entirely at some point in diary keeping, both of them giving as reasons social demands or pressures. These two terminations are in contrast to the eleven occasions'inarking the beginning of drinking. (These beginners may have had earlier alcohol experience, but presumably they have not had anything to drink recently.) These figures combined suggest that during the diary period more students began or increased their alcohol use than decreased it; on the other hand, for most students there appears to have been no great change.

Regarding alcohol outcomes, we find that the most prevalent is a positive effect as reported on more than half (54 per cent) of the drinking occasions. No effects are also common and are reported on 36 per cent of the occasions. Bad outcomes are reported on 13 per cent of the occasions.

Amphetamines. Eleven per cent of the panelists in School I, 5 per cent in School II, and 33 per cent in School IV record having taken amphetamines on diary-keeping days. Each amphetamine-taking student averages twenty-five amphetamine-taking occasions in School I, five occasions in School II, and 6.5 in School III. This means an average use in Schools I and II of amphetamines once every three and a half days to four days for those few students taking the drug. In School IV, the illicit-use panel, occasions occur on the average of once a week. The most common pattern in each school is to use amphetamines less than six times a week, although the few intensive users in School I are more likely, proportionately, to take them between seven and fourteen times per week; in fact, about one third of the occasions for use are concentrated in episodes seven to fourteen times per week in School I. Given such intensive use, then other periods must be slack, and we conclude periodicity or acute cycles for use rather than steady and regular use.

The time of day varies considerably by school. In School I the prevalent period is mornings; in School II it is mealtimes; in School III it is evenings. Most students deny any social use of amphetamines; the only exceptions are in School IV, where on three occasions use was a group drug experience. In School I intensive use is almost entirely the consequence of medical prescription; very few occasions are inspired by "mind-expansion" individual aims. In School II all use is medical; in School IV, where very little use is medical, psychedelic aims predominate along with individual interest in effects or in pleasure seeking per se.

During the panel period, initiation of amphetamine use (where it had not been in use previously or had been used long ago and was now resumed) took place most often in School IV. Here we find this innovation attributed to pleasure seeking and also to the availability of the drug. Illness, as such, accounts for its initial use only in School II. Escape motives appear only in School I. Increase in use (in contrast to initiation) is in School I linked to illness, whereas in School IV it occurs under group pressure, for pleasure, or when an amphetamine supply becomes available. There are no reports of diminished but continuing use, but in two schools termination did occur; one student in School I was unable to get a supply and one in School IV also quit after finding himself "oppressed" by methedrine.

Amphetamine effects are reported as positive on 88 per cent of the occasions, nil 7 per cent, and negative 5 per cent. Most negative effects are recorded in School IV (where social-hedonistic-psychedelic use is paramount) ; no ill effects are noted in School II, where use is entirely medical.

Sedatives. Eleven per cent of the panelists in School I and none in either II or IV record having used sedatives on diary-keeping days. We find thirty-seven sedative-taking occasions among these (N = 1), nearly all of them occurring at a rate of frequency of six times or less per week. One diary period reports seven to fourteen sedative-taking occasions during one week. Most ingestion is in the morning; bedtime ranks second. Almost all use is medically prescribed, although one finds one instance of use because of curiosity and four occasions when the student medicated at home without a doctor's advice. Most occasions for drug taking, even though medically prescribed, are described as social ones—that is, others are present (roommates and so on) even though social motives are not involved. Half of those using sedatives record a decrease over the six-month period, decreases being attributed to the healing of illness and the reduction of tension. With regard to effects, most occasions (80 per cent) of use are said to lead to desired effects, a few to no effects at all (17 per cent), and 3 per cent to ill effects.

Tranquilizers. Eleven per cent (N = 4) of School I students, 4 per cent (N = 1) of School II, and 11 per cent (N = 4) of diary keepers from School IV report using tranquilizers on diary days. In actual numbers these amount to ninety-nine tranquilizer-taking occasions, the frequency of which are twice as great per person at School IV as at School II. The most prevalent pattern for tranquilizer use is in the range of one to seven times a week. Almost all use at School
I is at bedtime; in contrast, at School IV, bedtime, morning, and afternoon use are about even. In School IV use is in a family setting; in School I students say they take the drugs when they are alone. Medical prescription is given as the paramount reason for tranquilizer use, although on a third of the occasions students say they self-administered tranquilizers because of psychological distress.

During the panel period three students report beginning tranquilizer use, each for reasons of tension or distress; during the same period, two say they stopped use, one as tension subsided and the other when what he considered an experiment was at an end. With reference to effects, the most common effect is stated as nil—this in 62 per cent of the cases. In 27 per cent of the cases, students report obtaining a desired effect, while in 11 per cent they record bad outcomes.

Other Drugs. In their diaries we asked students to record the use of other mild agents such as aspirin, Cope, and Endin, as well as prescribed drugs that are not psychoactive—or at least not designed to be that—which would include antibiotics, birth-control pills, and the like. We find 55 per cent of School I panel, 82 per cent of School II panel, and 67 per cent of School IV panel recording either prescription or over-the-counter analgesic or stimulant (No-Doze and so on) drug use. There are 896 reported occasions of such use on diary days for the sixty-seven students in the using group. The daily incidence of use approximates a rate of one occasion of use per student every third day. The most prevalent pattern indicates no more than six occasions for use during any one week, with only 7 per cent of the occasions involving use more than seven times per week. Drug taking is fairly evenly distributed during the day; mornings rank first, evenings second, mealtime third, afternoons fourth, and bedtime fifth. Drugs are reportedly consumed for the most part when the student is alone. Almost all use is self-prescribed; only 9 per cent of the occasions recorded for use appear based on medical advice and prescription.

In their use of common drugs, most students are continuing long-standing habits; those initiating the use of a new drug (or renewing an old one) do so primarily with the onset of illness or because of recommendations from friends or relatives; psychological distress is also a factor. The same factors account for increases 4m use over normal intake. Diaries indicate very little decrease in use during the panel span; two students diminished drug intake when their illness passed and one, in response to advice, stopped taking a drug entirely. The general picture which emerges is one of continuing or intermittent use of over-the-counter remedies by the majority of panelists. Medical prescriptions as such play a minor role in drug taking as do—we infer—clearly defined physical illnesses. With regard to effects, 62 per cent are reported as those desired, 34 per cent are reported as nil, and 4 per cent are reported as bad outcomes.

Marijuana. Seventeen per cent of the panelists in School I, 4 per cent in II, and 89 per cent in IV record having used marijuana on diary days. (Keep in mind that panelists in School IV were selected because of known high illicit-drug use.) In School I we find that use amounts to forty-eight occasions for six students on a total of about 250 diary days; average use by this 17 per cent amounts to once every fifth day. In School II, one student records having tried marijuana once. In School IV, the 412 occasions recorded mean, on the average, that users have taken marijuana on two to three days each week. The predominant pattern is of use less than six times a week, which suggests regularity rather than acute periodicity in use. In most cases marijuana is taken in the evenings, although in School IV students report 8 per cent as morning occasions. In School I most use is alone whereas in IV 85 per cent of the use is social. The sociability of purpose, or the sharing of experience, is emphasized by students in School IV, although we should note that those using it in School I indicate having social factors in mind—the implication being that even when taken alone, marijuana is preparatory for some upcoming social event. Among individual functions for the drug, the pleasure-giving one is most often cited, although 14 per cent of the School IV panelists say they use the drug in an attempt to relieve psychological distress.

In the sample four students, as best we can determine, began marijuana use for the first time during the panel period. This number would represent 4 per cent of all panelists. Twelve per cent indicate having increased their consumption during the panel period, most of them because of pleasure seeking or increased availability of supplies. Thirteen record having decreased consumption at one time or another, some because of social pressures, some because of reduced availability, and some because their curiosity was satisfied. Three mention having quit use during the panel period, one because of social pressure (which includes awareness of risk or disapproval) and two because their "experiment" was complete.

With regard to effects, students view 90 per cent of the occasions as leading to benefits and 6 per cent to bad outcomes; 4 per cent of the students report no effects at all.

Hallucinogens. Three per cent (N = 1) in School I, none in School II, and 44 per cent in School IV record use of hallucinogens (mostly LSD). One student (3 per cent) in School I reports two occasions of use over the forty-two diary days, or use once every three weeks. In School IV, the selected high-illicit-use panel, students report using a hallucinogen, on the average, once every ten days. Evening use is recorded as the most common, followed by mornings and then afternoons. Most occasions are in the company of close friends; a few are with the family; a few are alone. Panelists emphasize the importance of the group's sharing the drug experience and, among individual goals, cite pleasure the most frequently, although mind-expansion, self-exploration, curiosity, and the like also figure.

A number of increases in hallucinogen use are recorded as having occurred during the panel period. Nine students in School TV report having tried LSD and three, DMT for the first time. The reasons for use are related primarily to individual interests and not to drug availability or social pressures. Four students remark on a diminished use which they attribute to social pressures or to the end of their experimentation. Three others speak of having quit during the period for these reasons and in one case apparently also because of worry over use and effects.

With regard to effects, 80 per cent recorded desirable effects, 3 per cent no effects, and 17 per cent bad outcomes. This proportion of bad outcomes is greater than for any other recorded drug.

Opiates. We find no panel members mentioning illicit-opiate use in their diaries.

Special Substances. Three students, two in School I and one in School IV, recorded using drugs classified as special substances—banana peel in one case at School IV and Cylerti for the two cases in School I. One student in School I reports using Cylert every day for a week without positive effects. The other student, again in School I, says he tried Cylert once as a study aid with positive effects. (He remained awake all night writing a term paper.) Interestingly, the student using banana peel—which we believe to be inactive pharmacologically—on a single occasion says he felt no ill effects. Use of Cylert was alone, while the use of banana was in a group; motives for using the latter were social as well as individual, while for the former, mental alertness was the stated desire. All students report beginning their use of these special substances during the diary keeping period.

COMMENT

Clear differences exist among the panelists in each school. Some reflect the obviously successful selection of students for their illicit-drug-use propensities in School IV, while others presumably reflect the variations in student and campus characteristics discussed in earlier chapters. In the two panels selected randomly—and thus, at least, moderately representative of undergraduates in Schools I and II—alcohol is said to be the most widely used single drug. Even so, during the study period more than a fourth of the students in Schools I and II report they did not drink at all. (We did not ask students to record tobacco use.) Some inkling of future alcohol problems exists in both schools among those students drinking with high frequency in order to relieve psychological distress. Ill effects from alcohol are also not uncommon, occurring as a response to 13 per cent of all drinking occasions.

Self-medication with mild analgesics and over-the-counter stimulants and tranquilizers accounts for the second most frequent kind of drug use, although, of course, many different substances are reported as involved. The pattern of use is rather frequent and chronic self-medication for a majority of students, with interschool differences again emerging.
Among the legitimate drugs, one finds few panelists using sedatives, tranquilizers, amphetamines, or nonpsychoactive prescriptions obtained from physicians. Most panelists using these drugs do not take them often, although one diary records intensive sedative use for

one week and several show intensive amphetamine use over short periods.

Concerning illicit-drug use, we find even among the randomly selected panelists that marijuana is the most popular drug—one that they use more often than tranquilizers, for example. However, it is not used intensively in Schools I or II, and indeed in School II—noted in earlier chapters for its low rate of illicit-drug use—only one student reports having tried it and then only once. The sample selected because their early interviews revealed them to be high illicit users (School IV) shows a remarkably different pattern. There, twice as many panelists take marijuana as drink alcohol (at least on diary days) and they also use marijuana more often, two to three times a week compared with only once a week for liquor.

Hallucinogen use is the second most popular drug experience among the panelists of School IV. Almost half the students there average a hallucinogen, usually LSD, once every ten days. Illicit-amphetamine use is ranked third in popularity, occurring among one third of the panelists on the average of once a week.

The information about styles of use of amphetamines reflects on the uncertainty raised in earlier chapters about our arbitrary classification of these drugs—whether as approved or illicit. Recall from Chapter Seven that initial sources for amphetamine use were distributed almost equally among legitimate and illicit-informal sources (for example, doctors and parents vs. friends). We now see that the choice of styles of use varies by campus, just as drug experience itself varies. The distribution of amphetamine-use styles for our panelists is equally divided, with half of the occasions involving the use of amphetamines legitimately prescribed for a diagnosed disorder and the other half being used without medical prescription or approval and involving "mind-expansion," hedonism, or other private goals—or group understandings.

When we consider the reasons entered in the panelists' diaries for their illicit-drug use at the time of occurrence—or shortly after—we find that pleasure seeking is the overriding and self-identified private motive for marijuana use (75 per cent of all occasions) and the most frequent single "motive" offered for hallucinogen use (50 per cent of all occasions). For amphetamine use, pleasure seeking is the reason given for 18 per cent of the drug-use occasions. The relief of distress is important only for marijuana use and that on 14 per cent of the occasions. "Mind-expansion," as separate from pleasure, figures primarily in amphetamine use on 75 per cent of the occasions and on 16 per cent of the hallucinogen occasions. Although a variety of other reasons are also given, they are minor in terms of frequency and lead us to conclude that, whatever other reasons for illicit-drug use are offered and whatever secondary functions for drugs are noted—as we saw in earlier chapters—the pursuit of pleasure as an individual'goal is paramount.

Two other considerations are brought to bear, however: one is the social setting for use and the second, outcomes. Most marijuana use is a group event described by panelists as important in its shared drug experience; hallucinogens are also primarily taken as part of a social experience, as are amphetamines when these are used without medical prescription. Thus, whatever private pleasure may be attributed to the users' goals, these cannot be divorced from the pleasures of a social experience as such or—if not all group experiences are "pleasant"—then not from the fact that these drugs are taken with other people whose presence is recorded as an important component in the reason for use.

When we speak of the reasons for drug taking, there is a presumption of a means-end relationship, or "reward" or "reinforcement" in the sense of motives and learning—that is, ordinarily one expects the actual effects to matter. It is important to observe that such is not always the case. The efficacy of drugs—defined here in terms of what panelists entered in their diaries as positive, negative, or no effects—vary considerably from class to class. For example, almost two thirds of the occasions of tranquilizer use are described as having no outcomes, and one third of the occasions of the use of alcohol and over-the-counter remedies as leading to no remarkable effects. Curiously, no effects as such are rarely recorded for the illicit drugs—even though other observers have noted how often initial marijuana use leads to few noticeable effects and also that at least some of the marijuana use in California is known to be (Hollister, 1968) inactive—that is, without identifiable tetrahydrocannabinol content. In any event, no effects as such are recorded for less than 5 per cent of the use occasions of the amphetamines, marijuana, and the hallucinogens. We wonder whether these drugs are really that good or whether, as we suspect, a student who has committed himself to an illicit—and quite possibly to himself—dramatic act wants to admit that it has all been for naught, at least pharmacologically speaking.

As we consider the high rate of no outcomes for the tranquilizers and for home-remedy drugs, we should make one observation. (Our guess is that the unfelt effects of alcohol require little discussion, given the social significance of most drinking occasions among students—parties, dates, festive meals, seminars over beer, and so forth.) This observation is that people who use drugs do not need the reinforcement of an always noticeable drug effect in order to continue their use. What this implies is that drug use will continue in many instances even if effects are not felt. We can speculate as to the reasons. (1) Intermittent perceived efficacy of drugs may, like variable schedules of reinforcement in instrumental conditioning, serve to produce learning and to sustain behavior. (2) Some effects may occur which lead to conditioning even if the effects are subliminal, autonomic, or simply denied. One has in mind autonomic conditioning as such and demonstrations of subliminal reinforcement as devices capable of producing and maintaining behavior. (3) As long as the expectations for effects are maintained, these orientations or "hopes" may serve to induce behavior even when outcomes are nil. As long as advertising, peers, parents, doctors, and others continue to communicate their expectations, one acts in ways that are compatible with what others expect—as a good patient, child, and so on. One may continue such behavior even in the absence of authorities and one may also continue in order to reinterpret effects occurring in interpersonal settings so as to teach himself to "notice" what he failed to notice before. Becker (1963) describes this well for marijuana-use learning. We have also seen it among LSD users (Blum and Associates, 1964). (4) Drug ingestion as such can be satisfying, just as the group experiences associated with symbolic drug use can be satisfying, without regard to pharmacological outcomes. The satisfactions of ritual expressions are associated with act and context and not with perceived later internal effects. Whether on the level of gratification of oral needs, of "taking care of oneself" as taught by one's parents, of "being a good sport" and trying something new, or of being "regular" as some laxative users desire, what one is told and tells himself about the meaning or utility of use can be quite a sufficient cause for use. There can, of course, be a more complex psychodynamics associated with ingestion, as is often found among those compulsively ingesting food or what-have-you. Further investigation of these effects are in order.

Regarding the negative effects reported, we see that these are most frequent for hallucinogens and less frequent for alcohol. Curiously, none of the reasons offered by those very few persons diminishing or stopping drug use refers to negative effects specifically, although
one LSD user did stop because he was worried about the resulting post-trip depression and confusion. That negative effects can occur without deterring use is a common observation for psychoactive drugs.
First experiences with alcohol, tobacco, heroin, opium, and LSD are often unpleasant but yet drug novitiates continue use. This is a poorly understood but important phenomenon deserving further investigation. Whether these negative outcomes that are part of continuing or
even expanding use—with alcoholics or, for that matter, with others — may occur with simultaneous gratifications, as has been shown with acute LSD reactions (Katz, Waskow, and Olsson, 1968) or with the curious phenomenon of almost-achieving which we identified in those continuing LSD use (Blum and Associates, 1964), remains to be seen.

A final comment is in order with reference to the prevalence of marijuana use among panelists in the two "representative" panels. The 4 per cent using marijuana on diary days over six months in School II squares with the overall 11 per cent experience rate in that school and with the maximum rate of use2 during any given year (prevalence), which is, for twenty and twenty-one year olds, about 3 per cent. In School I the prevalence of marijuana use on diary days among 17 per cent of the sample is high in comparison with the overall sample experience rate of 21 per cent and in view of the maximum use reported for any one year, which is 11 per cent among twenty year olds. One explanation may lie in sampling error and a consequent error of estimate because of the small size of the panel sub-sample. While granting that possibility, we hasten to say that the trend is in conformity to other data that suggest the higher percentage be accepted. In the first place, at least one (3 per cent) of the panelists began marijuana use during the panel period, most of which was in point of time after the completion of the survey in School I (done in the autumn). Secondly, Chapter Eleven shows that by 1968 in School I a much higher prevalence of marijuana experience existed than during the early survey period of 1966. That increase in School I is compatible with very great increases in rates of arrest for juvenile drug offenses for California as a whole—a 176 per cent increase from 1966 to 1967,3 and supports a generalization from School Ito other Western student populations as well. In further support of the inference of increase, we would note that Chapter Eleven data show no increase in LSD use, which remains, according to these later survey findings, at about 6 per cent and which, among panelists, occurred in only one case, or 3 per cent.

In light of the foregoing, we must warn that other such increases are likely to have occurred in the other schools between the time of the survey and the time of publication of this report. For this reason we would recommend caution in relying on these figures as related to prevalence of experience. We further suggest that as use increases so that what was unusual behavior becomes usual, then the differences between students who take marijuana and those who do not become less consequential. When large numbers of people engage in common behavior, individual differences are to be expected within the group. Thus, consideration of differences between marijuana smokers and nonsmokers, as derived from our material in earlier chapters, must also be muted because what one is dealing with is no longer an individual but, rather, a general social phenomenon, the greater number of determinants of which are to be sought in shared social-environmental experiences instead of in the idosyncratic psychological sphere.

1 Cylert, magnesium pemoline, was at one time popularized as an aid to memory and learning (Spencer, 1966).

2 This is a statistic we have not given in earlier chapters. For other major age groups in School II, the figures are 2 per cent use among eighteen year olds with no regular or considerable use, 4 per cent among nineteen year olds with less than 1 per cent regular use, 3 per cent among twenty year olds with no regular or greater use, 3 per cent among twenty-one year olds with no regular or considerable use, and 1 per cent among twenty-two year olds with no regular use or greater.
For School I the prevalence of use by age is as follows: 4 per cent among eighteen year olds with no regular use; 9 per cent among nineteen year olds with 1 per cent regular use; 11 per cent for twenty year olds with 1 per cent regular or considerable use; 7 per cent among twenty-one year olds with 1 per cent regular or considerable use; and 1 per cent use among those twenty-three and over, with less than 0.5 per cent using marijuana regularly.
For School III, prevalence among eighteen year olds is as follows: 9 per cent with 3 per cent regular or considerable use; 12 per cent among nineteen year olds with 2 per cent regular or considerable use; 6 per cent among twenty year olds with 3 per cent regular or more use; 4 per cent among twenty-one year olds with 2 per cent regular or considerable use; and 2 per cent among twenty-two year olds with 1 per cent regular or greater use. In the twentythree-and-over group it is also 2 per cent with 1 per cent regular or considerable use.
For School IV the figures are as follows: eighteen year olds show 8 per cent with 2 per cent regular or considerable use; nineteen year olds show 11 per cent use with 7 per cent regular or considerable; twenty year olds show 14 per cent use with 8 per cent regular or considerable; twenty-one year olds show 16 per cent with 4 per cent regular or no considerable use; twenty-two year olds show 8 per cent use, 2 per cent of which is regular and none considerable; and in the range of the twenty-three to twenty-seven year olds there is 11 per cent use of which 4 per cent is regular or considerable.
In School V, prevalence of use among eighteen year olds is less than 1 per cent with no regular use; among nineteen year olds 3 per cent with no regular use; among twenty year olds 2 per cent and no regular use; twenty-one year olds show less than 1 per cent use. There is 1 per cent use among twenty-two year olds and again none regular, and there is 2 per cent among the group twenty-three and over, none of which is regular.

3 California Bureau of Criminal Statistics, April 1968 report.