That's not accurate (if it were, we wouldn't have efficacy rates for coitus interruptus and the rhythm method that this can be directly compared to, which we do

That's not accurate (if it were, we wouldn't have efficacy rates for coitus interruptus and the rhythm method that this can be directly compared to, which we do); but the rate is per year, not per act. From the link: >When used correctly every time you have sex, male condoms are 98% effective. This means 2 out of 100 people will become pregnant in 1 year when male condoms are used as contraception. On the other hand, over 20 years, that translates to an efficacy rate of only 67%.