Germany’s BBSR, the country’s Federal Institute for Research on Building, Urban Affairs and Spatial Development, put together the above population map from 2001-2011 data.
Areas of blue show population loss, and areas of red show population gain, Darker blue more loss (annual population decline of 2 percent or more), darker red means more gain (annual additions of 2 percent or more. Beige areas are in neutral.
The basic story is that the blue bits are showing rapid rural to urban migration. and exodus to other EU countries, and the red bits are swelling from that movement as well as international migration from outside the region.