There were 21,920 households . Of these , 34.60 % had children under the age of 18 living with them , 49.10 % were married couples living together , 17.90 % had a female householder with no husband present , and 28.80 % were non-families . There were 21,920 households out of which 34.60 % had children under the age of 18 living with them , 49.10 % were married couples living together , 17.90 % had a female householder with no husband present , and 28.80 % were non-families .