I wanted to get numbers on this, but naturally it's not feasible to get accurate numbers on corruption happening. I found the Corruption Perceptions Index which seems to be the closest we have in quantization. By measuring perceptions of corruption, as opposed to corruption itself, the Index may simply be reinforcing existing stereotypes and cliches though.

But according to their results the "west" has the least perceived corruption.

https://en.wikipedia.org/wiki/Corruption_Perceptions_Index