The population density was . There were 6,436 housing units at an average density of . The racial makeup of the city was 97.0% White, 0.5% African American, 0.1% Native American, 0.9% Asian, 0.3% from other races, and 1.1% from two or more races. Hispanic or Latino of any race were 1.6%. Of the 6,198 households 33.7% had children under the age of 18 living with them, 61.7% were married couples living together, 7.7% had a female householder with no husband present, 2.2% had a male householder with no wife present, and 28.3% were non-families. 25.0% of households were one person and 11.1% were one person aged 65 or older. The average household size was 2.50 and the average family size was 3.02. The median age was 43.4 years. 25.4% of residents were under the age of 18; 4.4% were between the ages of 18 and 24; 22.6% were from 25 to 44; 32% were from 45 to 64; and 15.5% were 65 or older. The gender makeup of the city was 47.5% male and 52.5% female. Of the city's population over the age of 25, 56% hold a bachelor's degree or higher. At the 2000 census there were 16,087 people in 6,239 households, including 4,685 families, in the city. The population density was 3,473.4 people per square mile (1,341.5/km²). There were 6,401 housing units at an average density of 1,382.1 per square mile (533.8/km²). The racial makeup of the city was 89.0% White, 9.3% African American, 0.01% Native American, 0.7% Asian, 0.01% Pacific Islander, 0.2% from other races, and 0.7% from two or more races. Hispanic or Latino of any race were 1.0%. 21.6% were of German, 20.4% Irish, 10.6% English, 8.6% Italian and 5.1% Polish ancestry according to Census 2000. Of the 6,239 households 34.1% had children under the age of 18 living with them, 65.8% were married couples living together, 17.4% had a female householder with no husband present, and 24.9% were non-families. 22.1% of households were one person and 9.6% were one person aged 65 or older.