1990 census data

Looking at USA age groups. What is the importance of this information to teachers and tax payers and medical people and retailers and . . .

age span	population	percent	kid / yr
1 - 4	18,264,096	7.3%	4,566,024
5 to 9	18,126,896	7.3%	4,531,724
10 to 13	13,881,633	5.6%	3,470,408
14 to 17	13,333,914	5.4%	3,333,479
18 to 24	26,234,880	10.5%	4,373,720