Marines don't fly Apaches, the Army does, so Marine age data is completely irrelevant.

Helicopter pilots in general trend older than ground grunts, due to training requirements and so on. And many of the Apache pilots in Iraq were/are reservists, so they trend older as well.

The first female Apache pilot already had 20 years of service when she was assigned to an Apache. The oldest British Apache pilot is 54.

It's not something some kid does right out of highschool. There are no teenagers flying Apaches.

I don't know, which is why I said "a good chance", but my estimate would be that the average Apache pilot is in their 30s.