The fourth and present wave of Filipino immigration began in 1965 with the passing of the Immigration and Nationality Act of 1965. It ended national quotas, and provided an unlimited number of visas for family reunification. By the 1970s and 1980s the immigration of Filipina wives of service members reached annual rates of five to eight thousand. The Philippines became the largest source of legal immigration to the United States from Asia. Many Filipinas of this new wave of migration have migrated here as professionals due to a shortage in qualified nurses; from 1966 until 1991, at least 35,000 Filipino nurses immigrated to the United States. As of 2005, 55% of foreign-trained registered nurses taking the qualifying exam administered by the Commission on Graduates of Foreign Nursing Schools (CGFNS) were educated in the Philippines. Although Filipinos made up 24 percent of foreign physicians entering the U.S. in 1970, Filipino physicians experienced widespread underemployment in the 1970s due to the requirement of passing the ECFMG exam to practice in the U.S.