The 95-97% success rate for condoms relates to the percentage of women (3-5%), using only condoms, who will become pregnant if they use them for one year.
Now *that* makes sense. That is the kind of statistic one could measure with accuracy, because nearly all pregnancies are accounted for. Presumably those are healthy, normal women in the prime childbearing age group. What is the natural rate without any contraception?
- Jed
