2007 estimate). Males had a median income of $45,535 versus $31,389 for females. The per capita income for the county was $24,789. About 4.90% of families and 6.60% of the population were below the poverty line, including 8.30% of those under age 18 and 7.90% of those age 65 or over. The leading ancestry group in Plymouth County is Irish, with 31%. Plymouth County, along with Norfolk County, Massachusetts, claims the highest percentage of people with Irish ancestry in the United States. 2010 census At the 2010 census, there were 494,919 people, 181,126 households, and 127,925 families in the county. The population density was . There were 200,161 housing units at an average density of . The racial makeup of the county was 85.5% white, 7.2% black or African American, 1.2% Asian, 0.2% American Indian, 3.2% from other races, and 2.6% from two or more races. Those of Hispanic or Latino origin made up 3.2% of the population. In terms of ancestry, 33.7% were Irish, 15.8% were Italian, 15.3% were English, 7.3% were German, and 3.7% were American. Of the 181,126 households, 35.1% had children under the age of 18 living with them, 53.6% were married couples living together, 12.6% had a female householder with no husband present, 29.4% were non-families, and 23.8% of households were made up of individuals. The average household size was 2.67 and the average family size was 3.18. The median age was 41.1 years. The median household income was $73,131 and the median family income was $86,251. Males had a median income of $60,303 versus $43,837 for females. The per capita income for the county was $33,333. About 5.0% of families and 7.0% of the population were below the poverty line, including 8.3% of those under age 18 and 7.0% of those age 65 or over. Demographic breakdown by town Income The ranking of unincorporated communities that are included on the list are reflective if the census designated locations and villages were included as cities or towns. Data is from the 2007–2011 American Community Survey 5-Year Estimates. Government and politics Elected Officials Plymouth County is governed by three County Commissioners: Chairman Jared L. Valanzola (R-Rockland) , Commissioner Sandra M. Wright (R-Bridgewater), and Commissioner Gregory M. Hanley (D-Plymouth) Other county elected officials include Sheriff Joseph D. McDonald, jr. (R-Kingston), District Attorney Timothy Cruz (R-Marshfield), Treasurer Thomas J. O'Brien (D-Plymouth), Register of Deeds John R. Buckley, jr.