When I was in school back in the 90s, I think by sixth or seventh grade most of the girls I knew had some form of sexual encounters with boys already. A few even lost their cherries to boys that didn't know the first thing about wearing a condom. In my school in particular, the girls locker rooms were a great place to sneak off for "couples privacy" as we had full stalls for changing.

Our gym teacher was a rather handsome man too, it wouldn't surprise me if a few girls had private meetings in his office but it never occurred to me to ask and nothing of the sort was ever shared in my presence.
Getting back on a more serious track though, instead of a hard number on AoC, maybe it would be better to have some form of certificate of sexual education or something similar to that effect. Make the penalties for actual rape harsher, include coercion/manipulation.
Maybe while we're at it, we can get rid of age requirements for viewing and participating in pornography.