Germany is well known to have big problems with the aging population, and its very low fertility rate. This contributes to a highly deformed population pyramid, where the lowest part of the pyramid is becoming thinner and thinner, while the middle section is significantly increasing, as well as the upper part of the pyramid that becomes thicker and thicker because of the long lifespan in the country.
In the next twenty years, Germany will face stagnation in the number of population, and this will be because the minorities (mainly the Muslims) will be balancing the numbers because of their very high fertility rate. In the next 50 years, with this trend, we will witness a big drop in the numbers of the ethnic Germans, and very big increase in the numbers of the minorities (mainly Muslims) which will also contribute to the country's population to start to increase again.