Silver Book Fact
Dementia prevalence was found to increase with age, from 5% of those Americans aged 71-79 years to 37.4% of those aged 90 and older.
Anderson G. Chronic Conditions: Making the case for ongoing care. Washington, D.C.: PhRMA; 2007. http://www.fightchronicdisease.org/sites/default/files/docs/ChronicCareChartbook_FINAL_0.pdf