[B Knotts]

Some of the other numbers seem off, as well. That graphic claims 15% in Austria. CIA Factbook reports 4.2%.

[Grzegorz 246]

In Poland according to the most "optimistic" estimations that's 0.1% and half without citizenship. Not much welfare, so they don't go there. 15% in Austria ? Not possible, but what could you expect from a source called theislamproject.org ?
On the other hand in France at least 9% and Spain 2-3%.