In the decades following the Korean War, there were a handful of high-profile defections from North to South Korea and vice versa, but the total number of people who voluntarily resettled from one state to the other was very small.
During the late 1990s, as North Korea experienced famine and economic collapse, a growing number of North Koreans fled to China to secure their livelihoods, with some eventually making it to the South. The number of North Koreans arriving in the South reached a peak in 2009.
After 2011, the number of North Koreans arriving in South Korea dropped by about 50% from this peak. Some cite tightened border security as the primary reason for this downturn, although relatively improved economic conditions in North Korea and an anti-defection propaganda campaign within North Korea may also be contributing factors.
The majority of North Koreans who have resettled in the South have been women, who currently account for about 70% of the North Korean population in South Korea. The lower participation rate of women in North Korea’s formal labor force may account for some of this gender imbalance.
Click following link for charts: North Korean Resettlement in South Korea