 Of the population in the municipality, 1,568 or about 31.9% were born in Wünnewil-Flamatt and lived there in 2000.There were 957 or 19.5% who were born in the same canton, while 1,478 or 30.1% were born somewhere else in Switzerland, and 732 or 14.9% were born outside of Switzerland., children and teenagers (0–19 years old) make up 26.9% of the population, while adults (20–64 years old) make up 61.8% and seniors (over 64 years old) make up 11.3%.