Nine-year secondary education in Russia is compulsory since September 1, 2007. Until 2007, it was limited to nine years with grades 10-11 optional; federal subjects of Russia could enforce higher compulsory standard through local legislation within the eleven–year federal programme. Moscow enacted compulsory eleven–year education in 2005, similar legislation existed in Altai Krai, Sakha and Tyumen Oblast. A student of 15 to 18 years of age "may" drop out of school with approval of his/her parent and local authorities, and without their consent upon reaching age of 18. Expulsion from school for multiple violations disrupting school life is possible starting at the age of 15.