I was bored so heres peoples ages:
note: i did not include halves or anything also im going by the age of the time in this post

12 or under -2
13 -2
14 -3
15 -2
16 -5
17 -7
18 -4
19 -6
20 -5
21 -9
22 -3
23 -0
24 -2
25 -2
26 and over -1

the most commen age is 21


and i may have made slight mistakes, also for the dude who wrote in japanese i didnt include your age cause i was too lazy to go back and check itachi's