Demography of city of Apex,NC As of the census of 2000, there were 20,212 people, 7,397 households, and 5,584 families residing in the town. The population density was 1,918.2 people per square mile (740.4/km2). There were 8,028 housing units at an average density of 761.9/sq mi (294.1/km2). The racial makeup of the town was 85.06% White, 7.55% African American, 0.29% Native American, 4.27% Asian, 0.06% Pacific Islander, 1.11% from other races, and 1.67% from two or more races. Hispanic or Latino of any race was 3.21% of the population. There were 7,397 households out of which 46.1% had children under the age of 18 living with them, 66.2% were married couples living together, 7.2% had a female householder with no husband present, and 24.5% were non-families. 18.5% of all households were made up of individuals and 2.6% had someone living alone who was 65 years of age or older. The average household size was 2.73 and the average family size was 3.16. In the town the population was spread out with 30.8% under the age of 18, 5.4% from 18 to 24, 44.8% from 25 to 44, 15.0% from 45 to 64, and 4.0% who were 65 years of age or older. The median age was 31 years. For every 100 females there were 97.8 males. For every 100 females age 18 and over, there were 94.0 males. The median income for a household in the town was $71,052, and the median income for a family was $78,689 (these figures had risen to $81,545 and $91,326 respectively as of a 2007 estimate). Males had a median income of $55,587 versus $37,057 for females. The per capita income for the town was $28,727. About 1.2% of families and 1.9% of the population were below the poverty line, including 1.2% of those under age 18 and 7.8% of those ages 65 or over.