We have a much older crowd as the belts go up... (not form natural belt progression though haha).
So most of the whitebelts are young, where all of our purple belts are at least thirty or so.
We have A LOT of 34+ year olds. One 50 something purple belt who works harder than anyone (comes every day) - and two brown belts who I'd guess are over 40.
Also have a 40 something blackbelt.
Somewhere in the LA area, or maybe in the bay area not sure, is a 55+ year old (probably older) blackbelt. I think he trains at Dave Camarillo's - that guy has the 600lb bear strength we were talking about earlier.