Just looking as is jungle win rate is kinda cheating.. His overall win rate is: https://gyazo.com/790d32ac36dcb3870502b008c3ade2c4.png Also I think his W changes are what helped him not thornmail.
he got buffed in last patch in case you weren't aware
selfslow from 60 to 30%
Contrary to popular belief, Rammus actually has higher winrate since 7.14 went live.