Resident Population in Delaware County, IA was 17.60000 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Delaware County, IA reached a record high of 18.93300 in January of 1980 and a record low of 17.05700 in January of 2019. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Delaware County, IA - last updated from the United States Federal Reserve on May of 2024.