Education is compulsory from 6 through 15 years of age, when students attend elementary school. After completion of this stage, most students continue their education at a general secondary school or a vocational secondary school, both of which offer four-year programs. Others enter teacher-training institutes, which require two to four years to complete. Under Communism, all schools were run by the government. In 1990 the establishment of private and religious schools was legalized. Although most schools in the Czech Republic are still state controlled, there are now more than 50 private elementary schools and more than 200 private secondary schools.