I think a better question would be what are the age ranges of people who go to, and pass INDOC.
Even then, people have different skills and abilities which relate to age, both good and bad. If there was a "profile" that you could just select successful PJ candidates from, they could save a lot of money on INDOC, and just train people to be successful.
There are guys from 18 to 38 who have gone to and passed INDOC, I'm 35 today, and know there are a couple of more of us "old" guys who will try to go to INDOC next year. Maybe my age, experiences, wisdom and desire will help offset my average athletic ability....