continue their education had to go study abroad. After Bulgaria overturned the Ottoman rule in 1878, it started laying the foundations of its educational system. In 1878 the government passed the Temporary Law on National Schools. This law stimulated the establishment of schools in villages. However, many peasants did not let their children attend school because they thought education was not relevant to peasant life. Furthermore, several universities were established in the period 1878 - 1918. Educational process in Bulgaria was disrupted during the Balkan Wars (1912 - 1913) and World War I. By the mid-1920s normal function of schools had been restored. During the communist era, the Soviet Union had a great impact on Bulgarian educational system. A new form of education was brought in. Emphasis on liberal arts was replaced by increased technical training. In 1979 Zhivkov created the Unified Secondary Polytechnical School, which was a twelve-grade program focusing mainly on technical subjects. After the end of the Zhivkov Era, the Bulgarian educational system was completely reconstructed. The government sought to depoliticize the system and take the opinions of others into consideration. Structure of the educational system The system consists of four levels: Preschool education Pre-primary education (preschool education) accepts children between 3 and 6/7 years old, who attend kindergarten optionally, with the requirement that prior to starting school, children must attend three years of pre-school education. During the school year 2007/2008, 74.8% of children aged 3–6 years were enrolled in kindergartens. Primary education Elementary education (grades 1 - 7) includes primary school (grades 1 - 4) and junior high school/ middle school (grades 5 - 7). Children usually start primary education at age 7, but may be start from age 6 upon their parents' request. Certificate for Primary Education and Certificate for Elementary Education are obtained upon successful completion of grade 4 and 7 respectively. High schools use grades from the Certificate for Elementary Education as a major admissions criterion. Secondary education Secondary education comprises selective/comprehensive high schools and vocational school. The admission to comprehensive schools is based upon grades from entry exams, usually in literature and/or mathematics as well as grades in junior high school. Students can enroll in high school after the successful completion of grades 7 or 8 (for students who finished school before 2017). Usually, those who want to study languages, mathematics, or informatics in-depth apply to high school after 7th grade. Students