sentences:  In terms of ancestry, 38.2% were German, 12.6% were Irish, 12.5% were American, and 9.3% were English.Of the 13,001 households, 32.5% had children under the age of 18 living with them, 57.4% were married couples living together, 9.2% had a female householder with no husband present, 29.0% were non-families, and 24.1% of all households were made up of individuals.The average household size was 2.53 and the average family size was 2.99.