the rest of the world is already far ahead of China - and you are right about testing: we only know about those that are tested, which are usually the bad cases that have symptoms and had been in contact with confirmed persons, and/or traveled in infested regions. And we know how many died, but we don't know the "dark numbers", so we cannot really calculate percentages unless we have more tests.
I doubt very much that the numbers in Russia, for example, are as low as are shown.
You can check details out here: https://www.worldometers.info/coronavirus/ - go to the list of countries here: https://www.worldometers.info/coronavirus/#countries