Tanzania is an East African country formed in 1964 as a sovereign state through the union of the separate states of Tanganyika and Zanzibar. The capital is Dodoma, as it is centrally located in the country. However, the largest city is the port-city called Dar es Salaam which remains the location for much of the government activity. In 1965 the Interim Consitution established the United Republic of Tanzania, and a permanent constitution was approved in 1977 and amended in 1984 with the Bill of Rights. The United Republic president is head of state and commander in chief, and there is a cabinet of ministers to advise the president. In 1995 an amendment was made to rescind the former stipulation to include the president of Zanzibar as one of the two vice-presidents. The country was a one-party state until 1992 when the constitution was amended to include multiparty elections. The government-supported education system has three levels: primary, secondary, and university. During the mid-1970s, universal primary education was made mandatory. The country has several universities and an extensive adult education system focused on reducing illiteracy. More than two-thirds of the population is literate, which is above average for the continent.