Uzbekistan is governed under the constitution of 1992 as amended. The president, who is head of state, is popularly elected and may serve two terms. The president's term was extended from five to seven years by a 2002 constitutional amendment, then reduced to five years again by a 2011 amendment. The government is headed by the prime minister, who is appointed by the president. There is a bicameral legislature, the Supreme Assembly. Of the 100 members of the Senate, 84 are elected by regional councils and 16 are appointed by the president. Of the 150 members of Legislative Chamber, 135 are popularly elected; 15 seats are reserved for the Ecological Movement of Uzbekistan. All legislators serve five-year terms. In practice, most opposition parties are banned, opposition figures are monitored and frequently jailed, and the president rules in an autocratic manner. Administratively, Uzbekistan is divided into 12 provinces or wiloyats, one autonomous republic (the Karakalpak Republic), and the capital city.