Below is a topology loosely based on the Library of Congress Classification System (http://lcweb.loc.gov/catdir/cpso/lcco/lcco)
... 34.0% from 18 to 24, 17.6% from 25 to 44, 20.5% from 45 to 64, and 14.1% who are 65 years of age or older. The median age is 28 years. For every 100 females there are 82.8 ...