Under the 1992 Constitution, Cabo Verde is a multi-party state, although the formation ofparties on a religious or geographical basis is prohibited. Legislative power is vested in the Assembleia Nacional (National Assembly), which comprises 72 deputies, elected by universal adult suffrage for a five-year term. The head of state is the President of the Republic, who is elected by universal suffrage for a five-year term. Executive power is vested in the Prime Minister, who is nominated by the deputies of the National Assembly, appointed by the President, and governs with the assistance of a Council of Ministers. A constitutional revision, adopted in July 1999, granted the President the right to dissolve the National Assembly, created a new advisory chamber (Conselho Economico e Social—Economic and Social Council), and granted the state the right to adopt Crioulo as the country's second official language. A series of further amendments to the Constitution were approved by the National Assembly on 9 February 2010.