According to the federal Bureau of Justice Statistics, in 2010, state corrections institutions spent $37.3 billion to imprison a total of 1,316,858 inmates. BJS estimates that the mean expenditures per capita was $28,323. There was a wide range in state spending: the bottom 25th percentile averaged only $21,417, the 50th percentile averaged $29,094, and the 75th percentile averaged $40,175.

Source

Kyckelhahn, Tracey, "State Corrections Expenditures, FY 1982-2010" (Washington, DC: US Dept. of Justice Bureau of Justice Statistics, Dec. 2012), NCJ239672, Table 2, p. 4.
http://www.bjs.gov/content/pu…