 , the gender distribution of the population was 48.7% male and 51.3% female.The population was made up of 8,466 Swiss citizens (81.2% of the population), and 1,961 non-Swiss residents (18.8%) Of the population in the municipality 1,727 or about 18.4% were born in Oberwil and lived there in 2000.There were 1,457 or 15.6% who were born in the same canton, while 3,916 or 41.8% were born somewhere else in Switzerland, and 1,954 or 20.9% were born outside of Switzerland.