Discovered and claimed by Portugal in the late 15th century, the islands' sugar-based economy gave way to coffee and cocoa in the 19th century - all grown with African plantation slave labor, a form of which lingered into the 20th century. While independence was achieved in 1975, democratic reforms were not instituted until the late 1980s. The country held its first free elections in 1991, but frequent internal wrangling between the various political parties precipitated repeated changes in leadership and two failed coup attempts in 1995 and 2003. In 2012, three opposition parties combined in a no confidence vote to bring down the majority government of former Prime Minister Patrice TROVOADA. The new government of Prime Minister Gabriel Arcanjo Ferreira DA COSTA is entirely composed of opposition party members with limited experience in governance. New oil discoveries in the Gulf of Guinea may attract increased attention to the small island nation.