Population rates

For a country's population to remain stable, the birthrate per woman should be at 2.1 children. The current birthrate of Europe as a whole is at 1.38, with certain countries, such as Spain, as low as 1.1. It is no stretch of the imagination to see that this is a drastic population drop. That's like, what, nearly a halved population every generation? The scary, though slightly amusing, thing is that the muslim population in Europe is headed in quite the opposite direction. They see children as a good thing, and in a number years, perhaps a generation or two, we could be looking at a largely muslim Europe. Freaky, no?