What age did you get thick?

Hey guys just wondering what age everyone noticed a natural girth increase. I got a small one at 16 but now at 18 am slowly noticing more gains again, anyone know what to expect? What age did you guys finish getting girth and how much did you get?

Starting 4/15/15 7.3 BPEL and 4.9 MEG

Super lazy and inconsistent :(