[ThePhysicist]

So far population in Germany keeps increasing, as it is one of the most popular countries for immigrants worldwide (and I'm not talking about refugees), so there's a large influx of people from within the European Union as well as from outside of it. Currently there are around 200.000 more deaths each year than births, which is still easy to compensate through immigration. Concerning the birth rate Germany is maybe a bit ahead of the curve, but the problem is similar in most Western countries, even the US. Recently birth rates have been increasing again by the way, so it's not clear if the historically low rates will prevail in the long run.

Also, the fact that education is free isn't really related to demographics, in fact University education has always been free, and the only attempt to introduce a (very moderate) tuition fee in 2006 was fully reversed a few years later due to pressure from various organizations.