"With far less notice, the number of people on probation or parole has skyrocketed to more than 5 million, up from 1.6 million just 25 years ago. This means that 1 in 45 adults in the United States is now under criminal justice supervision in the community, and that combined with those in prison and jail, a stunning 1 in every 31 adults, or 3.2 percent, is under some form of correctional control. The rates are drastically elevated for men (1 in 18) and blacks (1 in 11) and are even higher in some high-crime inner-city neighborhoods."
Source
Pew Center on the States, "One in 31: The Long Reach of American Corrections," (Washington, DC: The Pew Charitable Trusts, March 2009), p. 1.