In 2010, there were 340,523 family households, out of which 33.5% had children under the age of 18 living with them, 60.0% were Marriage living together, 11.7% had a female householder with no husband present, and 24.1% were non-families. 20.1% of all households were made up of individuals and 15.1% had someone living alone who was 65 years of age or older.  The average household size was 2.94 and the average family size was 3.38. The population was 23.3% under the age of 18, and 18.7% who were 62 years of age or older.  The median age was 41.1 years. For every 100 females, there were 93.7 males.  For every 100 females age 18 and over, there were 90.4 males.. How many percent do not have children under the age of 18 living with them?