 In terms of ancestry, 47.9% were German, 24.3% were Norwegian, 11.9% were Irish, 6.9% were English, 6.1% were Dutch, and 2.0% were American.Of the 12,029 households, 25.9% had children under the age of 18 living with them, 45.6% were married couples living together, 6.1% had a female householder with no husband present, 44.9% were non-families, and 29.6% of all households were made up of individuals.The average household size was 2.36 and the average family size was 2.93.