2000 census
As of the census [15] of 2000, there were 22,008 people, 8,778 households, and 5,951 families residing in the county. The population density was 30 people per square mile (12 people/km2). There were 9,505 housing units at an average density of 13 units per square mile (5.0 units/km2). The racial makeup of the county was 97.71% White, 0.53% Black or African American, 0.13% Native American, 0.40% Asian, 0.03% Pacific Islander, 0.43% from other races, and 0.77% from two or more races. 1.50% of the population were Hispanic or Latino of any race.
There were 8,778 households, out of which 30.40% had children under the age of 18 living with them, 56.80% were married couples living together, 7.40% had a female householder with no husband present, and 32.20% were non-families. 28.20% of all households were made up of individuals, and 15.00% had someone living alone who was 65 years of age or older. The average household size was 2.41 and the average family size was 2.96.
In the county, the population was spread out, with 25.00% under the age of 18, 8.60% from 18 to 24, 24.90% from 25 to 44, 22.40% from 45 to 64, and 19.00% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 97.50 males. For every 100 females age 18 and over, there were 95.10 males.
The median income for a household in the county was $32,453, and the median income for a family was $39,960. Males had a median income of $27,493 versus $20,099 for females. The per capita income for the county was $17,271. About 8.20% of families and 10.80% of the population were below the poverty line, including 12.30% of those under age 18 and 12.00% of those age 65 or over.
United States
Iowa 
