If you read in English, chances are that there are a few countries that take up the vast majority of your reading. Only 2-4% of books published in English are translated, and even books published in English in countries other than the U.S. and UK often don't get picked up and publicized in the same way that U.S. American works do.
This is even more pronounced when it comes to children's books, where the same books top the charts year after year. Parents tend to buy and read to their kids the same books their parents bought and read to them. If you want to branch out, though, and discover children's books published all across the world, here's a great place to start!