1. World Health Organization. World health statistics 2010. Geneva, Switzerland: WHO Press; 2010.
2. US Census Bureau. Annual estimates of the resident population by sex and five-year age groups for the United States: April 1, 2000 to July 1, 2009. Retrieved October 15, 2010 from
http://www.census.gov/popest/national/asrh/NC-EST2009-sa.htmlv
.
3. Arias E. Changes in life expectancy by race and Hispanic origin in the United States, 2013–2014. NCHS Data Brief. 2016;(244):1–8.
4. Christensen H. What cognitive changes can be expected with normal aging? Aust N Z J Psychiatry. 2001;35:768–75.
5. Christensen H, Mackinnon A, Jorm AF, Henderson AS, Scott LR, Korten AE. Age differences and interindividual variation in cognition in community-dwelling elderly. Psychol Aging. 1994;9:381–90.