An interesting statistic is the relative percentage of the US population of working age (i.e., ages 25-64, to be conservative) and those 65 and over, based on US Census Bureau data and projections. The percentage of the population aged 65 and over is currently about 19%, but is expected to increase to 26% by 2070. This has implications for how the OASDI (Old-Age, Survivors, and Disability Insurance) program is funded.
Link: https://www.census.gov/data/tables/2023/demo/popproj/2023-summary-tables.html