2000 31,705 1990 29,797 1980 30,419 1970 27,006 1960 24,061 1950 21,613 1940 19,912 1930 19,182 1920 20,709 1910 20,483 1900 22,913 1890 24,507 1880 25,977 1870 29,741 1860 25,036 1850 23,916 1840 16,614 1830 11,465 1820 8,038
As of the census of 2000, there were 31,705 people, 12,148 households, and 8,430 families residing in the county. The population density was 88 people per square mile (34/km²). There were 13,386 housing units at an average density of 37 per square mile (14/km²). The racial makeup of the county was 96.19% White, 1.45% Black or African American, 0.24% Native American, 0.59% Asian, 0.02% Pacific Islander, 0.39% from other races, and 1.12% from two or more races. 1.05% of the population were Hispanic or Latino of any race. 26.0% were of German, 25.7% American, 11.7% English and 9.7% Irish ancestry according to Census 2000.
There were 12,148 households out of which 32.00% had children under the age of 18 living with them, 55.00% were married couples living together, 10.60% had a female householder with no husband present, and 30.60% were non-families. 25.70% of all households were made up of individuals and 10.10% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 2.94.
In the county the population was spread out with 24.40% under the age of 18, 10.60% from 18 to 24, 28.50% from 25 to 44, 23.40% from 45 to 64, and 13.10% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 98.10 males. For every 100 females age 18 and over, there were 95.60 males.
The median income for a household in the county was $38,189, and the median income for a family was $45,712. Males had a median income of $31,618 versus $22,033 for females. The per capita income for the county was $17,412. About 7.60% of families and 9.60% of the population were below the poverty line, including 12.50% of those under age 18 and 8.40% of those age 65 or over.