Although most individuals self-report involvement in some form of delinquent or criminal behavior by early adulthood, official police records show a much smaller prevalence estimate (approximately 20-40 percent). For self-reported crime, prevalence peaks in the early teens; official records indicate the peak occurs in later adolescence. These data vary by crime type, with minor crimes peaking earlier and serious crimes peaking later. Studies that provide information on offending across race and gender tend to show that males and minorities (especially African-Americans) have an earlier and higher prevalence peak than females and Whites. Evidence on individual offending frequency (number of crimes committed per offender per year) is more mixed than the findings emerging from prevalence estimates. Individual offending frequency appears to vary according to several characteristics, including sample composition, measures of offending, and time periods observed. Annual individual offending frequency peaks in late adolescence; only a select few offenders have stable offending for a relatively long period. In addition, individual offending frequencies are higher for nonviolent than for violent offenses, but both decline over time. Most children and adolescents who engage in delinquent behavior do not go on to engage in criminal behavior as adults, and even fewer individuals who do not engage in delinquency as adolescents begin offending in adulthood. Research suggests that 30-60 percent of juvenile delinquents known to the police or juvenile court persisted in offending as adults. The most frequent offenders tend to show the strongest and longest continuity in their offending behavior; whereas less frequent offenders are less likely to continue offending. In general, these findings hold across samples, demographic characteristics (race and gender), time periods, and the length of observations.