I'll address your questions a bit later, but how can you call folks 50+ the smallest group? Like they're insignificant.
You've heard of the baby boomers, right?
Owners. Management.... predominantly older.
I guess, technically, by default, since the probability of death goes up with time, there are less folks over 50 than under. But you're talking about roughly 100 Million people. (Without me doing an exact count)