 Of the 20,373 households, 31.1% had children under the age of 18 living with them, 55.9% were married couples living together, 9.5% had a female householder with no husband present, 30.6% were non-families, and 26.1% of all households were made up of individuals.The average household size was 2.44 and the average family size was 2.92.The median age was 41.8 years.