In 1980 slightly more than 1 percent of the American adult population was under correctional supervision. The figure has since tripled to more than 3 percent, or one of every 32 American adults.

Although violent crime decreased during the 1990s, assault arrests increased by 28 percent, and drug-related arrests rose 34 percent. Arrests for embezzlement, forgery and fraud grew by 37 percent.

The largest increase came in the number of people placed on probation. Those convicted of drug-related offenses and such crimes as embezzlement, forgery and fraud are often given probation rather than incarcerated, meaning that the flow of inmates into prisons has largely stabilized.