Another way to look at it is to filter exchange based on their country/targeted country. At least for Asia it is quite easy to do so
If is that is easy to do so why aren't you showing us how the volume is looking for those countries?
Maybe because in reality nobody but the exchanges themselves know what numbers are reported?
And maybe even those numbers are fake as a lot are hiding under volumes that require KYC, VPN or even fake documents?
but for Europe it might be difficult since most exchanges accept registration from any country as long as it's within the continent.
There is zero difference other than the fact that some of the countries use the same currency.
Europe is by no means different than Asia, there is an exchange that doesn't accept certain countries like Kosovo or Albania, there are countries outside the SEPA program, there are countries with no financial regulation, don't look at Europe as a block, it's by no means such a thing.
In Binance exchange, Asian country Indonesia is leading in the trading volume as of this morning, its current trading volume is about $112b in the fiat market, but most of the time Nigeria volume do supersede sometimes.
And how you quantify for example the 1.3 trillion in the ETH/BTC pair?
As for the NGN, where did you get those billions in trade for the NGN?
BTC/NGN volume si 33BTC a day...