"Since peaking at 3,210 offenders per 100,000 U.S. residents age 18 or older in 2007 (not shown in tables), the correctional-supervision rate has trended downward, falling to 2,510 per 100,000 at year-end 2018 (table 4). Changes in both the correctional population and the U.S. population affected the rate. More than half (58%) of the decrease in the correctional-supervision rate from 2008 to 2018 was attributed to the decrease in the number of offenders under correctional supervision.

"The remainder (42%) of the decline was attributed to the increase in the U.S. resident population age 18 or older (not shown in tables). The correctional-supervision rate at year-end 2018 was the lowest it had been since 1992 (2,490 per 100,000; not shown in tables).

"At year-end 2018, an estimated 1,730 offenders per 100,000 adult U.S. residents were on probation or parole. This was similar to the rate in 1990, when the community-supervision population was smaller by about 1.2 million offenders and the adult U.S. resident population was smaller by almost 69 million persons (not shown in tables). Like the correctional-supervision rate, the community-supervision rate has declined for 11 consecutive years since peaking in 2007 (2,240 per 100,000; not shown in tables).

"In 2018, about 830 persons per 100,000 adult U.S. residents were under the jurisdiction of state or federal prisons or in the custody of local jails. This incarceration rate has declined since reaching a high of 1,000 per 100,000 adult U.S. residents from 2006 to 2008. The incarceration rate is currently at its lowest point since 1996 (830 per 100,000; not shown in tables)."

Source

Laura M. Maruschak and Todd D. Minton. Correctional Populations in the United States, 2017-2018. Bureau of Justice Statistics: Washington, DC. August 2020. NCJ252157.