however, if it is about online gambling, may be many people here are also playing it. But not in the real casino or offline casinos.
I doubt there would be accurate table and statistics here in online ganbling as most of us plays anonymously
These stats even won't near to the accurate value, this will be the mean value collected by most of the articles posted by individuals which means most of the countries won't get covered and it is impossible to keep track of the anonymous gambling as well.
We might have misunderstood what OP has posted, this is not about anonymous gambling sites or crypto casinos as there's no way we can track that information or even the regulators, so let's assume that these are all fiat casinos data summarize to come up with this list.