Silver Book Fact

Average annual prescription drug costs and sources of payment among noninstitutionalized Medicare enrollees age 65 and over, 1992-2004
Federal Interagency Forum on Aging-Related Statistics. Older Americans 2008: Key Indicators of Well-Being. Washington, D.C.: U.S. Government Printing Office; 2008. https://agingstats.gov/docs/PastReports/2008/OA2008.pdf