Figure 3.

Percentage of persons 25 years old and over, by highest level of educational attainment: Selected years, 1940 through 2009

SOURCE: U.S. Department of Commerce, Census Bureau, U.S. Census of Population: 1960, Vol. I, Part 1; Education of the American Population, a 1960 Census Monograph by John K. Folger and Charles B. Nam; Current Population Reports, Series P-20, various years; and Current Population Survey (CPS), March 1961 through March 2009.