Chongryon-affiliated organisations operate businesses and banks to provide jobs, services and social networks for Zainichi Koreans outside of mainstream society. In the 1970s and 1980s, these organizations constituted an important economic link between North Korea and Japan. The Chongryon-affiliated companies monitored the Tokyo Stock Exchange to enable the DPRK to sell its non-ferrous metals and other mineral products at the most advantageous prices, and purchased inexpensive Japanese consumer goods for re-export to the Comecon countries. Chongryon supporters are thought to control as much as one third of the pachinko industry in Japan. An important function of these enterprises is earning hard currency to be remitted to Pyongyang. These remittances have been estimated at between $600 million and $1.9 billion each year but are probably much lower. Chongryon announced plans on March 17, 2010 to open three restaurants in Pyongyang; each restaurant will be managed by the main headquarter in Tokyo, the Kantō regional chapter, and the Kinki-Tōkai regional chapter.