Silver Book Fact
In 2012, the 85-years-and-older population includes about 2.5 million people with Alzheimer’s disease, or 48 percent of the Alzheimer’s population age 65 and older.
Alzheimer's Association. 2012 Alzheimer’s Disease Facts and Figures. Alzheimers Dement. 2012; 8(2): 131-68. http://www.alzheimersanddementia.com/article/S1552-5260(12)00032-5/fulltext