http://www.realjock.com/article/1608The risk of becoming infected on any single occasion of receptive anal sex with internal ejaculation is 1.43 percent. If the partner withdraws before ejaculating, that risk goes down to 0.65 percent. The infection rate for each occasion of insertive anal sex (topping) is 0.11 percent if a man is circumcised; it goes up to 0.62 percent if a man is uncircumcised. The upshot: receptive anal sex with ejaculation is roughly twice as risky as receptive anal sex with pre-ejaculation withdrawal or topping by an uncircumcised man, and more than 10 times as risky as topping by a circumcised man.
The 60% stuff.....just scary.