Our list is getting pretty accurate, thanks to all. Germany, Italy still missing though
Rank Country Users 1 United Kingdom 1,300,000 2 France 480,000 3 Poland 280,000 4 Spain 200,000 5 Ireland 200,000 6 Lithuania 150,000 7 Greece 140,000 8 Romania 75,000 9 Hungary 50,000 10 Switzerland 50,000 11 Malta 50,000 12 Czech Republic 40,000 13 Belgium 30,000 14 Bulgaria 20,000 15 Cyprus 15,000 16 Norway 13,000 TOTAL 3,093,000
thanks @Dreamture