Aatrox's winrate - Why did it go down?

Why do you think it spiraled down all of a sudden? The changes didn't seem like a nerf to me. He's now in the bottom 5 for both top and jungle winrate wise, when a few patches ago he was in the middle of the pack.

http://champion.gg/champion/Aatrox/Jungle - Note how 125+ has a 38% winrate in the jungle. http://champion.gg/champion/Aatrox/Top - Started trending downward on patch 6.19. Again 125+ players are a bit low at 45.8% winrate.

I just find this odd considering a few patches ago he didn't have this downward trend.