Public expenditure of the GDP was less in 2002–05 than in 1991. Public education is theoretically free and mandatory for under-16-year-olds, but, in practice, expenses exist. In 2005 net primary enrollment rate was 44%, a significant drop from 79% in 1991. Education between ages nine and sixteen is compulsory. Pupils who complete six years of primary school and seven years of secondary school obtain a baccalaureate.