The Urbana Micropolitan Statistical Area includes all of Champaign County.
2000 38,890 1990 36,019 1980 33,649 1970 30,491 1960 29,714 1950 26,793 1940 25,258 1930 24,103 1920 25,071 1910 26,351 1900 26,642 1890 26,980 1880 27,817 1870 24,188 1860 22,698 1850 19,782 1840 16,721 1830 12,131 1820 8,479 1810 6,303
As of the census of 2000, there were 38,890 people, 14,952 households, and 10,870 families residing in the county. The population density was 91 people per square mile (35/km²). There were 15,890 housing units at an average density of 37 per square mile (14/km²). The racial makeup of the county was 95.73% White, 2.30% Black or African American, 0.31% Native American, 0.25% Asian, 0.02% Pacific Islander, 0.31% from other races, and 1.08% from two or more races. 0.69% of the population were Hispanic or Latino of any race.
There were 14,952 households out of which 34.00% had children under the age of 18 living with them, 59.70% were married couples living together, 9.20% had a female householder with no husband present, and 27.30% were non-families. 23.50% 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 2.56 and the average family size was 3.01.
In the county the population was spread out with 26.20% under the age of 18, 7.90% from 18 to 24, 28.70% from 25 to 44, 24.60% from 45 to 64, and 12.60% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 95.90 males. For every 100 females age 18 and over, there were 92.90 males.
The median income for a household in the county was $43,139, and the median income for a family was $50,430. Males had a median income of $38,265 versus $26,241 for females. The per capita income for the county was $19,542. About 5.10% of families and 7.60% of the population were below the poverty line, including 9.90% of those under age 18 and 7.60% of those age 65 or over.