which the school is located) or private, which may receive government subsidies. Private schools (subsidized or not) may be organized as either for or non-profit. In order to receive public funding, private schools must reserve 15% of seats in each class to students classified as "vulnerable" (based on family income and mother's level of education). Schools receive extra funding for each "vulnerable" student they enroll. Primary The 1965 reform established primary education as the initial cycle of schooling. Before that, by 1920, Chilean legislation had established four years of minimum mandatory education. By 1929 the minimum had been increased to six years. Since 1965, the primary level has been obligatory, with a current duration of 8 years in total divided into 2 cycles and 8 grades: 1st Cycle: 1st grade (age 6-7), 2nd grade (age 7-8), 3rd grade (age 8-9), 4th grade (age 9-10). 2nd Cycle: 5th grade (age 10-11), 6th grade (age 11-12), 7th grade (age 12-13), 8th grade (age 13-14). Secondary Secondary education is divided between Scientific-Humanist (regular), Technical-Professional (vocational) and Artistic, all lasting four years. The first two years are the same for the three kinds of schooling, while the third and fourth years are differentiated according to the orientation of the school. The schools offering Technical-Professional programs are denominated: Industrial Schools: electricity, mechanics, electronics, informatics, among others. Commercial Schools: management, accountancy, secretary and similar. Technical Schools: fashion, culinary, nursery and the like. Polyvalent Schools: offering careers of more than one of those listed above. Most of the students choosing the vocational branch come from disadvantaged socioeconomic background. Private school with subscribing-fees gathers less than 1% of the students. Compulsory education only covered the eight years of primary school, but in 2003 a constitutional reform established in principle free and compulsory secondary education for all Chileans up to 21 years of age. This ensured twelve years of compulsory schooling, which was an unprecedented milestone in Latin America at the time. Coverage The net enrollment ratio (covering students of school age) in 2009 was 93.19% in primary, and 70.70% in secondary, while the gross enrollment ratio (covering students of any age) was 106.24% in primary and 94.68% in secondary. Costs Voluntary tuition Public schools and subsidized private schools may charge a fee for the selection process, an annual price of enrollment (which, as of 2011, cannot be higher than CLP$3,500, or about US$7) and a monthly tuition fee