Industry was the favored sector. By 1957 industrial production reached 1949 levels. In 1959, relations with Japan had improved somewhat, and North Korea began allowing the repatriation of Japanese citizens in the country. The same year, North Korea revalued the North Korean won, which held greater value than its South Korean counterpart. Until the 1960s, economic growth was higher than in South Korea, and North Korean GDP per capita was equal to that of its southern neighbor as late as 1976. However, by the 1980s, the economy had begun to stagnate; it started its long decline in 1987 and almost completely collapsed after the dissolution of the Soviet Union in 1991, when all Soviet aid was suddenly halted.