sentences:  In terms of ancestry, 28.3% were German, 24.3% were American, 13.1% were Irish, and 11.7% were English.Of the 13,255 households, 32.3% had children under the age of 18 living with them, 55.0% were married couples living together, 9.7% had a female householder with no husband present, 30.8% were non-families, and 26.5% of all households were made up of individuals.The average household size was 2.47 and the average family size was 2.98.