The study found significant differences in the conviction rates over time for both males and females. There was a dramatic decline among the 10-15-year-old age group for more recent cohorts. This reflects the increasing use of court diversionary procedures for this age group. There was no corresponding increase in conviction rates for the older age groups. These statistical trends suggest that efforts in the 1980s and early 1990s in diverting offenders from formal court processing and convictions have been successful. Such diversionary schemes should be promoted and expanded. This study used the Offenders Index cohort data, specifically a subset of the Index that consisted of six birth cohorts. This involved all offenders born in four specified weeks (one in each of March, June, September, and December) in 1953, 1958, 1963, 1968, 1973, and 1978. Conviction histories were recorded until the end of 1999. There were just over 47,000 male offenders and 10,000 female offenders in the 6 cohorts. 1 figure, 5 tables, and 18 references