Polk County, Iowa

Polk County is a located in the  of. As of 2000, the population was 374,601. The 2006 estimate is 408,888. Its  is, which is also the capital city of Iowa. Polk County is one of the five counties that make up the.

Geography
According to the, the county has a total area of 1,533 (592 ). 1,475 km² (569 sq mi) of it is land and 58 km² (23 sq mi) of it (3.81%) is water.

Adjacent counties

 * (northwest)
 * (north)
 * (east)
 * (southeast)
 * (south)
 * (southwest)
 * (west)

Demographics
As of the of 2000, there were 374,601 people, 149,112 households, and 96,624 families residing in the county. The was 254/km² (658/sq mi). There were 156,447 housing units at an average density of 106/km² (275/sq mi). The racial makeup of the county was 88.34%, 4.84% or , 0.27% , 2.63% , 0.06% , 2.22% from , and 1.66% from two or more races. 4.40% of the population were or  of any race.

There were 149,112 households out of which 32.20% had children under the age of 18 living with them, 51.00% were living together, 10.30% had a female householder with no husband present, and 35.20% were non-families. 28.10% of all households were made up of individuals and 8.60% had someone living alone who was 65 years of age or older. The average household size was 2.45 and the average family size was 3.04.

In the county the population was spread out with 25.70% under the age of 18, 9.40% from 18 to 24, 32.20% from 25 to 44, 21.50% from 45 to 64, and 11.10% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 94.20 males. For every 100 females age 18 and over, there were 90.70 males.

The median income for a household in the county was $46,116, and the median income for a family was $56,560. Males had a median income of $37,182 versus $28,000 for females. The for the county was $23,654. About 5.30% of families and 7.90% of the population were below the, including 9.70% of those under age 18 and 6.40% of those age 65 or over.