In 2010, the city population was spread out with 18.8% under the age of 18, 9.4% from 18 to 24, 33.1% from 25 to 44, 25.0% from 45 to 64, and 13.6% who were 65 years of age or older. The median age was 38.8 years. For every 100 females, there were 99.2 males. For every 100 females age 18 and over, there were 98.1 males.. Which age group had the highest population in 2010?