My best guess (by age) based by my own percepction:

100% ages 3 to 5.

50% 6 to 8.

40% 9 to 14.

30% 15 to 20.

20% 21 to 30.

15% 31 to 45.

10% 46 to 65.

5% 66 to 75

1% > 75