SOURCE: U.S. Department of Education, National Center for Education Statistics,
Higher Education General Information Survey (HEGIS), "Fall Enrollment in Institutions
of Higher Education" surveys, 1970 through 1985; Integrated Postsecondary Education
Data System (IPEDS), "Fall Enrollment Survey" (IPEDS-EF:86–99); IPEDS Spring 2001
through Spring 2012, Enrollment component; and Projections of Education Statistics
to 2021. U.S. Department of Commerce, Census Bureau, Current Population
Survey (CPS), October, selected years, 1970 through 2011.