Well, if you're only talking primary, you're at least average with what I'm getting, 779 AP20s in ~11800 tasks (though that does include the previous AP26 search work which found 2 in an unknown number of tasks, but I think its effect is asymptotic to 0 at this point). My overall rate is higher (11%) if you allow for all AP2x, primary and secondary. As all random data has its clusters and voids, how's your total rate?
My math brain now wonders if there's an easy way to obtain data to calculate percentage-based mean/median/standard deviation information on results vs. tasks per user.
Eating more cheese on Thursdays.