The future and the young-old.
D000368:Aged; D005260:Female; D005544:Forecasting; D006262:Health; D006801:Humans; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D011158:Population Growth; D012179:Retirement; D012959:Socioeconomic Factors; D014481:United States; D014507:Urbanization