Since 1986, compulsory education in China comprises primary and junior secondary school, which together last for nine years.[364] In 2010, about 82.5 percent of students continued their education at a three-year senior secondary school. The Gaokao, China's national university entrance exam, is a prerequisite for entrance into most higher education institutions. In 2010, 27 percent of secondary school graduates are enrolled in higher education. Vocational education is available to students at the secondary and tertiary level.