"Looking at the numbers through the lenses of race and gender reveals stark differences. Black adults are four times as likely as whites and nearly 2.5 times as likely as Hispanics to be under correctional control. One in 11 black adults—9.2 percent—was under correctional supervision at year end 2007. And although the number of female offenders continues to grow, men of all races are under correctional control at a rate five times that of women."
Source
Pew Center on the States, "One in 31: The Long Reach of American Corrections," Washington, DC: The Pew Charitable Trusts, March 2009.