Education is compulsory at the primary level between ages 7 and 13; however, because of a lack of facilities, only 62% of primary-school-age children were enrolled in school in 1999. In 1998, there were 3,884 primary schools, in which 1,026,570 students were taught by 18,373 teachers. At the secondary level, 215,988 students were attending schools the same year. The pupil-teacher ratio at the primary level was 51 to 1 in 1999. The University of Dakar has two graduate schools and numerous research centers. For over 30 years, the University of Dakar offered free tuition and generous subsidies to students. However, in 1994 it began implementing new austerity measures aimed at scaling back enrollment, raising academic standards and getting students to pay for more of the cost of their education. A polytechnic college opened at Thiès in 1973. Other colleges include a national school of administration at Dakar and a school of sciences and veterinary medicine for French-speaking Africa. Universities and equivalent institutions had 24,081 students in 1994–95. Adult illiteracy remains high. The projected adult illiteracy rate for the 2000 stand at 62.7% (males, 52.8%; females, 72.4%). As of 1999, public expenditure on education was estimated at 3.5% of GDP.