2000 31,945 1990 31,111 1980 32,719 1970 30,813 1960 29,633 1950 28,673 1940 27,061 1930 27,635 1920 29,167 1910 30,407 1900 31,187 1890 28,939 1880 27,023 1870 18,714 1860 13,570 1850 8,251 1840 4,598 1830 210 1820 22
As of the census of 2000, there were 31,945 people, 11,963 households, and 8,134 families residing in the county. The population density was 68 people per square mile (26/km²). There were 12,907 housing units at an average density of 27 per square mile (11/km²). The racial makeup of the county was 97.54% White, 0.70% Black or African American, 0.25% Native American, 0.43% Asian, 0.23% from other races, and 0.85% from two or more races. 0.78% of the population were Hispanic or Latino of any race. 96.9% spoke English and 1.4% German as their first language.
There were 11,963 households out of which 31.40% had children under the age of 18 living with them, 55.00% were married couples living together, 8.90% had a female householder with no husband present, and 32.00% were non-families. 26.50% of all households were made up of individuals and 10.80% had someone living alone who was 65 years of age or older. The average household size was 2.51 and the average family size was 3.03.
In the county the population was spread out with 24.30% under the age of 18, 15.40% from 18 to 24, 26.00% from 25 to 44, 21.30% from 45 to 64, and 12.90% who were 65 years of age or older. The median age was 33 years. For every 100 females there were 95.90 males. For every 100 females age 18 and over, there were 92.70 males.
The median income for a household in the county was $34,440, and the median income for a family was $42,395. Males had a median income of $33,393 versus $21,695 for females. The per capita income for the county was $16,200. About 8.90% of families and 13.20% of the population were below the poverty line, including 15.20% of those under age 18 and 11.90% of those age 65 or over.