Korean currency
In 1902, won was introduced as the official currency unit replacing yang at 1 won = 5 yang. The bank of Korea was established 1909 but soon after in 1910, Imperial Japan annexed Korean Empire. Under Colonial rule, the country was made to use the currency unit "yen" in the name of Korean yen, which took over the Korean won at par. After the division of Korea, the state of South Korea was established and recognized in 1948, and won was again made the official currency of the new state. "jeon" was made the subunit of the currency that divided it into 100 equal parts. Bank of Joseon issued the currency for independent South Korea for the first time that too in banknotes only.
Dandong
A substantial portion of North Korea's international trade, both legal and illegal, passes through Dandong and Sinuiju, across the Yalu River in North Korea. China handles roughly 40% of North Korea's worldwide export trade ($1.58 of 4 billion USD) and roughly half of the bilateral commerce with China goes through Dandong which imports $468 million [USD worth of product], according to its Ministry of Commerce. Dandong's annual resident per capita wage income for 2004 was somewhere between ¥9,500 and ¥12,237 RMB and the city's GDP was 3.77 billion USD.