Population under 18 in Mason County
Population under 18 in Mason County was 19.8% in 2025, according to the U.S. Census Bureau. That is up 0.1 pts from 2024. That is the 71st highest of 102 counties in 2025.
Population under 18 in Mason County, 2010 to 2025
All 16 values
| Period | % |
|---|---|
| 2025 | 19.8 |
| 2024 | 19.7 |
| 2023 | 19.6 |
| 2022 | 20 |
| 2021 | 20 |
| 2020 | 20.2 |
| 2019 | 20.3 |
| 2018 | 20.3 |
| 2017 | 20.4 |
| 2016 | 20.5 |
| 2015 | 20.6 |
| 2014 | 20.8 |
| 2013 | 20.8 |
| 2012 | 21.6 |
| 2011 | 21.8 |
| 2010 | 22 |
Compared with Illinois and United States
| Place | 2025 |
|---|---|
| Mason County | 19.8 |
| Illinois | 20.6 |
| United States | 21.1 |
Rankings
Definition
Residents aged 0 to 17 as a percentage of total population on 1 July. United States: Census Bureau county population estimates by age; states and the nation are sums of their counties.
Uses the US age of majority. Not comparable with population_0_14_share, which stops at 14.
How to cite
U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.Use this data in your AI agent
Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:
What is the latest population under 18 in Mason County? Cite the source.
get_value {"indicator":"population_0_17_share","place":"us-county-17125"}
GET https://invokely.ai/api/v1/value?indicator=population_0_17_share&place=us-county-17125Questions
What is the population under 18 in Mason County?
Population under 18 in Mason County was 19.8% in 2025, according to the U.S. Census Bureau. That is up 0.1 pts from 2024. That is the 71st highest of 102 counties in 2025.
Where does this figure come from?
U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Retrieved by Invokely on 2026-10-12.
What was the highest population under 18 in Mason County?
22% in 2010, the highest value since 2010 in this series.