The U.S. prison population shrank in 2021, continuing a decade-long decline in the number of people who are incarcerated.

The total number of people held in prison or jail, as well as those under community supervision via probation or parole, went down by over 61,000, the Bureau of Justice Statistics said Thursday. 

That amounts to a decrease of only 1% from 2020 to 2021, but represents a 22% decline since 2011.

A bulk of the prison population’s drop over the past 10 years — 65% of it — is coming from the number of people going off probation. Those released from either prison or jail accounted for 26% of the decline.

BJS said the number of people under supervision by the end of 2021 was estimated at 3,745,000, down by 136,600 from the beginning of the year. The supervision rate fell to a 21-year low of 1,440 people on probation or parole per 100,000 adults in 2021. That number peaked in 2007 with 2,240 people per 100,000.

The probation population fell in 31 states and the federal prison system in 2021, while increasing in 18 states and the District of Columbia, according to the BJS. 

Adults on probation for serious offenses rose from 18% to 26% from 2011 to 2021. 

Meanwhile, the 803,200 people on parole by the end of 2021 represented a 7% decrease since the start of the year. It was the largest decrease in people on parole since 1992.

• Matt Delaney can be reached at mdelaney@washingtontimes.com.