Answer based on context:

In 2000, there were 149,957 households out of which 18.30% had children under the age of 18 living with them, 52.70% were Marriage living together, 7.70% had a female householder with no husband present, and 37.00% were non-families. 30.40% of all households were made up of individuals and 16.90% had someone living alone who was 65 years of age or older.  The average household size was 2.13 and the average family size was 2.61.

How many percent do not have children under the age of 18 living with them?
81.7