The person that was interviewed on Tucker some time back said 10%.
Suspect that number was low for 15-20%
World Population
7,761,740,282 - 25% for children 0-14
5,821,305,211
@10% 582,130,521
US Population
329,237,661 -25% for children 0-14
246,928,245
@10% 24,692,824