Equatorial Guinea is governed under the constitution of 1991 as amended. The president, who is head of state, is popularly elected for a seven-year term; a two-term limit was adopted in 2011. The government is headed by a prime minister, who is appointed by the president. The bicameral legislature consists of the 100-seat House of People's Representatives, whose members are elected to serve five-year terms. The Senate (first elected in 2013) has 70 members, 55 of whom are elected; the rest are appointed by the president. Members of the legislature are elected from multimember constituencies on a proportional basis. The legislature has little power, as the constitution vests most authority in the president. Administratively, the country is divided into seven provinces.