This rating is complex, and not only based on taxation. These ratings are based on such factors as the volume of trade and mining, the development of the legislative framework, institutions, the financial sector and central banks in the country.
To rank it with economical power and governmental prowess doesn't really make sense to me. I mean think about it, we are not seeing El Saldavor, the nation that made it a legal tender. I am not saying that you should ignore all the names there, some nations there are definitely good and there is no denying that. But at the same time, we should realize that many names are missing as well.
Nobody says that these names are bad, these names are good of course but at the very least we should know how it could miss some of the most important ones. India, El Salvador, Turkey, Nigeria all these are greatly friendly but not huge economically hence why they were left out.