Passage: The Republic of Cuba is one of the world's last remaining socialist countries following the Marxist–Leninist ideology. The Constitution of 1976, which defined Cuba as a socialist republic, was replaced by the Constitution of 1992, which is "guided by the ideas of José Martí and the political and social ideas of Marx, Engels and Lenin." The constitution describes the Communist Party of Cuba as the "leading force of society and of the state".The First Secretary of the Communist Party is concurrently President of the Council of State (President of Cuba) and President of the Council of Ministers (sometimes referred to as Prime Minister of Cuba). Members of both councils are elected by the National Assembly of People's Power. The President of Cuba, who is also elected by the Assembly, serves for five years and there is no limit to the number of terms of office.

Question: Cuba was designated a socialist republic in what year?
1976