"Open Doors" is a long-standing, comprehensive information resource on over 565,000 international students in the United States in 2004/05 and on over 191,000 U.S. students who studied abroad for academic credit in 2003/04. 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. Throughout the history of the Open Doors International Student Census, there have been periods of strong growth followed by plateaus, affected by both global and domestic political and economic events. For the second consecutive year, international student enrollment in U.S. higher education showed a decline, with a 1.3% drop in 2004/05, following a 2.4% drop in 2003/04. These declines followed a year of minimal growth, and two prior consecutive years of strong growth.