By the 1980s, the world economic socialist system embraced one-third of the world’s population but generated no more than 15 percent of global economic output. At its height in the mid-1980s, the world socialist system could be said to comprise the following countries with a "socialist orientation", though not all were allies of the Soviet Union: Afghanistan, Albania, Angola, Bulgaria, Cambodia, China, Cuba, Czechoslovakia, Eastern Germany, Ethiopia, Hungary, Mozambique, Nicaragua, North Korea, Laos, Mongolia, Poland, Romania, Vietnam, South Yemen, Yugoslavia and the Soviet Union.[76] The system co-existed alongside the world capitalist system but was founded upon the principles of cooperation and mutual assistance rather than upon competition and rivalry The countries involved aimed to even-out the level of economic development and to play an equal part in the international division of labour.