 31.9% were of German, 14.4% Swedish and 14.2% Norwegian ancestry.There were 8,638 households out of which 32.20% had children under the age of 18 living with them, 55.50% were married couples living together, 9.50% had a female householder with no husband present, and 30.50% were non-families.25.90% of all households were made up of individuals and 12.00% had someone living alone who was 65 years of age or older.