"The 55-years-and-older age group increased its relative share of the civilian noninstitutional population [age 16 years and older] from 26.3% in 1992, to 27.6% in 2002, to 33.0% in 2012 and is projected to be nearly 38.0% of that population in 2022," according to a 2013 analysis of Census Bureau data.
Toossi, M. (2013). Labor force projections to 2022: The labor force participation rate continues to fall. Washington, DC: Bureau of Labor Statistics. Retrieved from www.bls.gov.