Estimate, Median Age by Sex, Total Population (5-year estimate) in Cumberland County, IL was 43.10000 Years of Age in January of 2024, according to the United States Federal Reserve. Historically, Estimate, Median Age by Sex, Total Population (5-year estimate) in Cumberland County, IL reached a record high of 43.10000 in January of 2024 and a record low of 40.20000 in January of 2013. Trading Economics provides the current actual value, an historical data chart and related indicators for Estimate, Median Age by Sex, Total Population (5-year estimate) in Cumberland County, IL - last updated from the United States Federal Reserve on May of 2026.