I had a pretty bad year where my win rate dropped by roughly 3% while the rest of my stats went up while finishing grinding out 10 Tier X tanks plus a few new lines. But my most played tank was the Tier IX Japanese Medium Type 61.
Win 8, Damage per battle, Average XP per battle, WoT PR, survival rate and Hit Ratio all went up but winrate kept dropping. Just too many battles in tanks that as soon as they are spotted they normally melt like the Type 61 once it is spotted. Or playing tanks that are just too slow to relocate and get back to base when the other side of the map has fallen when you are over halfway across on your front when they start capping your base while your fast Meds and lights mess around else where looking for arty instead of going back. example tanks T95, VK 100.01P, T28 Proto and O-Ho.