Rape statistics almost uniformly carry the assumption that only male-on-female-rape outside of prison counts. It's often useful to point out the number of men in prison, and ask whoever gives you the first statistic if it balances.
http://www.ojp.usdoj.gov/bjs/abstract/pjim02.htmThe latest numbers were from mid-year 2002, when 665,000 Americans were in prison (discounting the 72,000 held outside of prisons), or 113 out of every 100,000 females and 1309 out of every 100,000 males. Throw in the state prisons and that number goes to 96,000 women and 1,330,000 men.
When you go somewhere like here:
http://www.paralumun.com/issuesrapestats.htmThe FBI estimates that 72 of every 100,000 females in the United States wereraped last year. (Federal Bureau of Investigation, Uniform Crime Statistics, 1996.)
How many men in prison get raped each year? How about a conservative estimate of 1 in 10. That's 133,000 rapes, or 130 per 100,000 men, in prison or out. That's just shy of double the FBI rate of raped women, and I wouldn't be surprised to find out that rate of rape in prison is a lot higher than 1 in 10, especially if you expand rape to include the wide array of sexual assaults that get hidden under that umbrella-term.