For males and females born in 1973, the proportion with at least one conviction was lower than for those born in earlier cohort years, reflecting increased cautioning of young offenders. Nearly 60 percent of all court appearances before the age of 40 for males born in 1953 were attributable to about 20 percent of offenders, or 7 percent of the male population. The majority of offenders had only one court appearance; 55 percent of male offenders and 78 percent of female offenders born in 1953 had only one court appearance. Of males and females born in 1953, 7 percent and 1 percent, respectively, had received a custodial conviction before the age of 40; 50 percent of male offenders and 70 percent of female offenders born in 1953 were first convicted of theft and handling stolen goods. The earlier a male offender had his first court appearance, the more likely he was to be convicted again. About 60 percent of male offenders had criminal careers of less than a year in length. The peak age of known criminal activity for males was 19 years, at which age 11 percent of those born in 1953 were known to be criminally active. 17 notes, 10 tables, and 11 figures