Only 65 percent of adult Pakistanis are literate. The constitution prescribes free primary education. While enrollment rate in primary school is high for boys, less than one-half of girls attend school. Five years has been established as the period of primary school attendance. In the 1996 school year 81 percent of primary school-aged children were enrolled in school, while only 30 percent of secondary school-aged children attended. In the early 1990s, 336,600 students attended institutions of higher education. Among Pakistan’s leading universities are the University of Karachi (1951), the University of the Punjab (1882), in Lahore; the University of Peshawar (1950); the University of Sind (1947), in Dadu; and the University of Agriculture (1909), in Faisalabad.