Silver Book Fact
Age of U.S. population in 40 years
The U.S. population 40 years from now is projected to have 20 percent aged 65 and over, and one-tenth of them aged 90 and over (that is, 2 percent of the total population).
He W, Muenchrath N. 90+ in the United States: 2006-2008. Washington, DC: US Census Bureau; 2011. https://www.census.gov/library/publications/2011/acs/acs-17.html