Economy of North Korea
Estimating gross national product in North Korea is a difficult task because of a dearth of economic data and the problem of choosing an appropriate rate of exchange for the North Korean won, the nonconvertible North Korean currency. The South Korean government's estimate placed North Korea's GNP in 1991 at US$22.9 billion, or US$1,038 per capita. In contrast, South Korea posted US$237.9 billion of GNP and a per capita income of US$5,569 in 1991. North Korea's GNP in 1991 showed a 5.2% decline from 1989, and preliminary indications were that the decline would continue. South Korea's GNP, by contrast, expanded by 9.3% and 8.4%, respectively, in 1990 and 1991.
Korean currency
The won was introduced in 1902, replacing the yang at a rate of 1 won = 5 yang. In 1909, the Bank of Korea was founded in Seoul as a central bank and began issuing currency of modern type. The won was equivalent to the Japanese yen and was replaced by the Korean yen in 1910. At the same time, Korean yen notes issued by Dai Ichi Ginko (First National Bank (of Japan), 株式會社第一銀行) also circulated.