At the 2000 Census, there were 6,670 people, 2,445 households, and 1,885 families residing in the city. The population density was 401.8 people per square mile (155.1/km2). There were 2,558 housing units at an average density of 154.1 per square mile (59.5/km2). The racial makeup of the city was 98.47% White, 0.27% African American, 0.15% Native American, 0.39% Asian, 0.03% Pacific Islander, 0.03% from other races, and 0.66% from two or more races. Hispanic or Latino of any race were 0.55% of the population. 18.5% were of German, 14.3% Italian, 12.0% Irish, 9.6% English and 6.2% Slovene ancestry according to Census 2000.