The decline and recovery of the European wolf population from 1800 to 2018 (no data for Russia and Belarus).
Map is a bit confusing since it has no data for Russia and Belarus, but there are wolves there. Here is another map with population numbers as well:
Source
Also, pretty infographic about wolves from the same source:
I'm surprised to see wolves didn't roam in the Netherlands before, a lot of people here are in favour of wolves (re-)introducing themselves here, as “wolves always used to live here and this is the natural order”