2000 14,566 1990 13,551 1980 14,844 1970 11,606 1960 11,502 1950 11,006 1940 10,775 1930 9,841 1920 10,144 1910 10,504 1900 10,448 1890 8,803 1880 8,167 1870 5,829 1860 2,360
As of the census of 2000, there were 14,566 people, 5,340 households, and 3,999 families residing in the county. The population density was 36 people per square mile (14/km²). There were 5,726 housing units at an average density of 14 per square mile (6/km²). The racial makeup of the county was 97.33% White, 0.17% Black or African American, 0.31% Native American, 0.22% Asian, 0.08% Pacific Islander, 1.14% from other races, and 0.76% from two or more races. 2.90% of the population were Hispanic or Latino of any race. 22.6% were of German, 14.3% American, 11.8% Irish, 10.0% English and 7.7% Polish ancestry according to Census 2000.
There were 5,340 households out of which 34.20% had children under the age of 18 living with them, 63.10% were married couples living together, 7.80% had a female householder with no husband present, and 25.10% were non-families. 20.90% of all households were made up of individuals and 9.40% had someone living alone who was 65 years of age or older. The average household size was 2.69 and the average family size was 3.12.
In the county the population was spread out with 26.40% under the age of 18, 7.90% from 18 to 24, 28.50% from 25 to 44, 24.40% from 45 to 64, and 12.80% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 98.80 males. For every 100 females age 18 and over, there were 96.60 males.
The median income for a household in the county was $40,944, and the median income for a family was $46,741. Males had a median income of $36,152 versus $20,780 for females. The per capita income for the county was $17,755. About 4.80% of families and 6.90% of the population were below the poverty line, including 6.20% of those under age 18 and 10.30% of those age 65 or over.