Zambia is governed under the constitution of 1991 as amended. The president, who is both head of state and head of government, is popularly elected for a five-year term and is eligible for a second term. The unicameral legislature consists of the 158-seat National Assembly; 150 members are elected by popular vote and eight are appointed by the president. All legislators serve five-year terms. Administratively, Zambia is divided into nine provinces.