These Are The Only Countries Whose Population Has Actually Declined Since 1990
Here's a startling map from Michael McDonough that speaks volumes about the global demographics situation. It shows the only countries that have seen their population decline since 1990.
As you can see, the countries are dominated by Soviet/Eastern Block countries. These countries are presumably afflicted by low birth rates and high emigration.
Here's the chart showing the specifics of which countries are in decline.