Figure 2.

Enrollment, total expenditures in constant dollars, and expenditures as a percentage of the gross domestic product (GDP), by level of education: Selected years, 1965–66 through 2006–07

NOTE: Expenditure data for school years 2004 through 2006 (2004-05 through 2006-07) are estimated. SOURCE: U.S. Department of Education, National Center for Education Statistics, Statistics of State School Systems, 1965-66 through 1969-70; Statistics of Public Elementary and Secondary School Systems, 1970 through 1980; Revenues and Expenditures for Public Elementary and Secondary Education, 1970-71 through 1986-87; Common Core of Data (CCD), "State Nonfiscal Survey of Public Elementary and Secondary Education," 1981-82 through 2005-06; "National Public Education Financial Survey," 1987-88 through 2004-05; Statistics of Nonpublic Elementary and Secondary Schools, 1970-71 through 1979-80; Private School Universe Survey (PSS), 1989-90 through 2003-04; Fall Enrollment in Institutions of Higher Education, 1965-66 through 1985-86; Financial Statistics of Institutions of Higher Education, 1965-66 through 1985-86; 1986-87 through 2004-05 Integrated Postsecondary Education Data System (IPEDS), "Fall Enrollment" surveys, 1986 through 1999, and Spring 2002 through Spring 2006 and Fall 2002 through Fall 2006; and Projections of Education Statistics to 2016.