Estimate, Median Age by Sex, Total Population (5-year estimate) in Vermilion County, IL was 40.80000 Years of Age in January of 2022, according to the United States Federal Reserve. Historically, Estimate, Median Age by Sex, Total Population (5-year estimate) in Vermilion County, IL reached a record high of 40.80000 in January of 2020 and a record low of 39.10000 in January of 2010. 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 Vermilion County, IL - last updated from the United States Federal Reserve on May of 2024.