There are 10 such instances. The latest happened in Oct 2016. The countries associated with the first nine countries are:
USA (1906), USA (1919), Egypt (1978), Costa Rica (1987), USSR (1990), South Africa (1993), South Korea (2000), USA (2009), and Liberia (2011).
What's the tenth and latest, and what are we talking about?
[+ Show Answer]
Nobel Peace Prizes won by sitting Presidents. The 2016 Peace Nobel was won by Colombia's President Juan Manuel Santos.
Here's the list.