There were 24,082 households out of which 27.3% had children under the age of 18 living with them, 44.3% were married couples living together, 9.1% had a female householder with no husband present, and 43.3% were non-families. 32.4% of all households were made up of individuals and 11.7% had someone living alone who was 65 years of age or older. The average household size was 2.31 and the average family size was 2.95. In the city, the population was spread out with 20.7% under the age of 18, 18.1% from 18 to 24, 29.7% from 25 to 44, 18.3% from 45 to 64, and 13.1% who were 65 years of age or older. The median age was 32 years. For every 100 females, there were 99.9 males. For every 100 females age 18 and over, there were 98.7 males. The median income for a household in the city was $37,636, and the median income for a family was $48,843. Males had a median income of $33,750 versus $24,154 for females. The per capita income for the city was $18,964. About 5.2% of families and 10.2% of the population were below the poverty line, including 8.6% of those under age 18 and 6.9% of those age 65 or over. Oshkosh is also served by the GO Transit (formerly Oshkosh Transit System), which runs nine fixed-route bus routes throughout the city from 6:15 AM until 6:45 PM Monday through Saturday. One of these routes also connects Oshkosh with Neenah, Wisconsin and the Fox Cities' transit system, Valley Transit. Oshkosh's airport, Wittman Field or Wittman Regional Airport (KOSH), opened in 1927 as Oshkosh Airport Inc. The airport had commercial traffic starting in 1928 when Northwest Airways delivered mail to Oshkosh and the Fox Cities. In 1972, the airport was renamed after race pilot Steve Wittman, who was the airport manager for 38 years. Wittman Field had commercial service on a number of airlines until 2003. Wittman was served at various times by Wisconsin Central Airlines, North Central, Republic, Air Wisconsin, American Central, Midstate Airlines, Northwest Airlink, United Express, Midway Connection, Skyway, and Great Lakes.