 The population density was 36 people per square mile (14/km²).There were 18,635 housing units at an average density of 18 per square mile (7/km²).94.5% of the population were White, 2.9% Asian, 0.6% Native American, 0.5% Black or African American, 0.2% of some other race and 1.3% of two or more races.