"Open Doors" is the only comprehensive information resource on over 547,000 international students in the United States and on the more than 143,000 U.S. students who studied abroad in 2000. 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.