As of the 2000 United States Census there were 338,391 people, 128,201 households, and 91,663 families in the county. The population density was 181/sqmi (70/km2). There were 136,954 housing units at an average density of 73/sqmi (28/km2). The racial makeup of the county was 91.27% White, 2.45% Asian, 0.71% Native American, 0.66% Black or African American, 0.17% Pacific Islander, 2.28% from other races, and 2.46% from two or more races. 4.95% of the population were Hispanic or Latino of any race. 20.7% were of German, 11.6% English, 9.1% Irish and 7.5% American ancestry.