The "white revolution" of the 1960s, which emphasized industrialization, involved the importation of petroleum technology and the training of Iranian technicians abroad, but it did not improve Iran's indigenous technology. The principal scientific institution in Tehran is the International Scientific Research Institute, founded in 1955. Specialized learning societies include the Iranian Mathematical Society and the Iranian Society of Microbiology, both headquartered in Tehran. Also in the city are the Animal Husbandry Research Institute and the Institut Pasteur. Iran has 37 universities offering degrees in basic and applied sciences. Following the removal of the Shah and the formation of an Islamic revolutionary government, Iran suffered a "brain drain" as foreign-trained scientists and engineers either fled the country or refused to return after their education. In 1987–97, science and engineering students accounted for 37% of college and university enrollments.