Middle East and Russia are in Asia as far as I was told in elementary school. Looking at a world map now some 18 years later, I can see that it's accurate :). Especially for Middle East.
But I can see your point, my take is that it's predominantly happens in Asia. There are some spots of it in Europe as well. Mostly the eastern european enclaves. But they will fall eventually (or be consumed by Russia)
Asia is simply home to most of the world's population. I suspect you will see the same everywhere that's not a 1st world country (which happen to mostly be in North America & Europe).
South America, Africa, (non-EU) Eastern Europe all suffer from this kind of corruption.
But I can see your point, my take is that it's predominantly happens in Asia. There are some spots of it in Europe as well. Mostly the eastern european enclaves. But they will fall eventually (or be consumed by Russia)