According to the U.S. Bureau of Justice Statistics (BJS), 2,266,800 adults were incarcerated in U.S. federal and state prisons, and county jails at year-end 2011 – about 0.7% of adults in the U.S. resident population.[7] Additionally, 4,814,200 adults at year-end 2011 were on probation or on parole.[11] In total, 6,977,700 adults were under correctional supervision (probation, parole, jail, or prison) in 2011 – about 2.9% of adults in the U.S. resident population.
The United States has the highest documented incarceration rate in the world (743 per 100,000 population), Russia has the second highest rate (577 per 100,000), followed by Rwanda (561 per 100,000)
http://en.wikipedia.org/wiki/Incarceration_in_the_United_Sta...