sentences:  Of the 21,535 households, 27.2% had children under the age of 18 living with them, 45.7% were married couples living together, 11.9% had a female householder with no husband present, 38.1% were non-families, and 32.3% of all households were made up of individuals.The average household size was 2.27 and the average family size was 2.84.The median age was 42.0 years.