Just to add a little elucidation to the sex-ed thing, the places that don't focus on abstinence as the only technique don't really explain the numbers. That's a 1% chance that after a year of regular sexual intercourse. Which makes the per-use numbers much, much smaller.

Furthermore, there was at least some issue in that many doctors were more conservative, and didn't really like talking about oral sex. (I heard this from a doctor who was complaining about this).