 35.9% identified as being of German, 24.4% as Norwegian and 7.0% as of Irish ancestry.There were 15,582 households out of which 29.70% had children under the age of 18 living with them, 54.70% were married couples living together, 8.00% had a female householder with no husband present, and 33.80% were non-families.29.10% of all households were made up of individuals and 14.80% had someone living alone who was 65 years of age or older.