If you're wondering about the population of Carter City, MO, you're not alone. According to the 2010 census, 29.9% of residents are never married, making this small town a little older than the national average. But the median age in Carterville is only slightly older than the national average - it's 32.3 years, versus 37.9 years for the country. And the population of people who are at least 18 years old is composed of 11.3% of veterans. This is higher than the national rate of 7.5%, which is eighteen percent.