"Open Doors" is a long-standing, comprehensive information resource on nearly 573,000 international students in the United States in 2003/04 and on the almost 175,000 U.S. students who studied abroad for academic credit in 2002/03. The Institute of International Education, the largest and most experienced U.S. higher education exchange agency, has conducted an annual statistical survey of the internationally mobile student population in the United States since 1948, with U.S. government support since 1972.