Resident Population in Decatur County, TN was 11.65600 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Decatur County, TN reached a record high of 11.72800 in January of 2016 and a record low of 9.30000 in January of 1971. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Decatur County, TN - last updated from the United States Federal Reserve on May of 2024.