It was my assumption at first that it was woman leaders, but South Korea stood out to me because they had never had a female president. Their Prime Minister for one year, however, was... but that kind of ignores the fact that the PM's position in South Korea is like what the Vice President is in the United States, perhaps even less so because I don't see the South Korean PM having any actual powers to exercise. As a matter of fact, South Korea's president is actually both the head of state and head of government.
The map is inaccurate so the question should be invalidated.