"A smaller percentage of female prisoners in 2015 were age 55 or older (7%) compared to males (almost 11%). The percentage of white female prisoners age 55 or older was higher for the other race groups of female prisoners. Twice as many white females (52,700 prisoners) than black females (21,700) were in state and federal prison at yearend 2015. However, the imprisonment rate for black females (103 per 100,000 black female residents) was almost double that for white females (52 per 100,000) (appendix table 4). Among any age group, black females were between 1.5 and 4.0 times more likely to be imprisoned than white females and between 1.1 and 2.0 times more likely than Hispanic females. As with males, females ages 30 to 34 had the highest rates of imprisonment of any age group (184 per 100,000 female residents)."

Table: Women in the US Sentenced and Serving Time in Either State or Federal Jurisdiction: 2000 and 2010-2015

Note: The Bureau of Justice Statistics defines Imprisonment Rate as "the number of prisoners under state or federal jurisdiction sentenced to more than 1 year per 100,000 U.S. residents."
a: Includes American Indians and Alaska Natives; Asians, Native Hawaiians, and Other Pacific Islanders; and persons of two or more races.
b: Excludes persons of Hispanic or Latino origin.

*: Number of women identifying as "other" not provided separately until 2012, so for 2000 and 2010-2011, this figure was derived by subtracting the number of non-Latina Whites, non-Latina Blacks, and Latinas from the total. As a result, the imprisonment rate is not available.

Source

Carson, E. Ann, and Anderson, Elizabeth. Prisoners in 2015. Washington, DC: US Dept of Justice Bureau of Justice Statistics, Dec. 2016. NCJ250229.