Israel has a school life expectancy of 16 years and a literacy rate of 97.8%. The State Education Law, passed in 1953, established five types of schools: state secular, state religious, ultra orthodox, communal settlement schools, and Arab schools. The public secular is the largest school group, and is attended by the majority of Jewish and non-Arab pupils in Israel. Most Arabs send their children to schools where Arabic is the language of instruction. Education is compulsory in Israel for children between the ages of three and eighteen. Schooling is divided into three tiers – primary school (grades 1–6), middle school (grades 7–9), and high school (grades 10–12) – culminating with ''Bagrut'' matriculation exams. Proficiency in core subjects such as mathematics, the Hebrew language, Hebrew and general literature, the English language, history, Biblical scripture and civics is necessary to receive a Bagrut certificate. Israel's Jewish population maintains a relatively high level of educational attainment where just under half of all Israeli Jews (46%) hold post-secondary degrees. This figure has remained stable in their already high levels of educational attainment over recent generations. Israeli Jews (among those ages 25 and older) have average of 11.6 years of schooling making them one of the most highly educated of all major religious groups in the world. In Arab, Christian and Druze schools, the exam on Biblical studies is replaced by an exam on Muslim, Christian or Druze heritage. ''Maariv'' described the Christian Arabs sectors as "the most successful in education system", since Christians fared the best in terms of education in comparison to any other religion in Israel. Israeli children from Russian-speaking families have a higher bagrut pass rate at high-school level. Amongst immigrant children born in the Former Soviet Union, the bagrut pass rate is higher amongst those families from European FSU states at 62.6% and lower amongst those from Central Asian and Caucasian FSU states. In 2014, 61.5% of all Israeli twelfth graders earned a matriculation certificate.