Fewer defectors from North to South Korea

According to South Korea's Unification Ministry, fewer North Koreans have defected to the South this year.  As shown in this chart published by Statista (click to see a larger version) "between January and August, 780 North Koreans managed to complete the dangerous journey and make it across the 38th parallel. The decline is being attributed to tighter border security by China (where most defectors flee) and North Korea as well as enhanced government surveillance by Pyongyang." The overall pattern shown in the chart is also striking, given that Kim Jong Il, father of the current ruler Kim Jong Un, was in power through most of 2011. The pattern of defections clearly changed after the younger Kim assumed power and executed a number of military and party leaders, including his own uncle.