This statistics looks shocking at the first glance, but many Balts are coming back from their Western jobs and building nice houses back home. Some migration is temporary. The idea that you make a lot of money in the West and come back home is fairly widespread in Central and Eastern Europe. IDK how many Poles worked abroad, but at the height of their exodus, there were several magazines just specializing in advertising foreign jobs. It didn't hurt Poland that much, though. Much of their money flew home as remittances and helped build the country.