As of the census of 2000, there were 20,237 people, 8,385 households, and 5,290 families residing in the city. The population density was 1,328.9 people per square mile (513.0/km2). There were 9,193 housing units at an average density of 603.7 per square mile (233.1/km2). The racial makeup of the city was 96.25% White, 0.14% African American, 1.65% Native American, 0.33% Asian, 0.02% Pacific Islander, 0.71% from other races, and 0.90% from two or more races. Hispanic or Latino of any race were 1.28% of the population. 47.1% were of German, 19.8% Norwegian and 5.9% Irish ancestry. 96.5% spoke English, 1.7% Spanish and 1.1% German as their first language.