Why do i only attract older men?

I'm 17 (18 at the end of November) and I only seem to attract guys age 30-50. Guys my age tend to ignore me most (but not all) of the time (about 99%). People tell me I look anywhere between 13-21 (my face is kind of ambiguous) but everyone has said that I'm really pretty (though I'm not trying to sound vain lol) and I tend to dress in neutral colours so I do not think I look promiscuous. My chest is impossibly flat (I'm a AA cup) and I'm about 108/109 Ibs at 5'5 so I'm not that tall (my legs are kind of long though). Essentially I think i look like an adolescent, however, these guys do not seem to know (or care). Why do you think this is the case