Where did you get the data? Are they public? I never knew the existence of the data publicly    Is there any valid reason why evil IP has suddenly increased in May 2017 while it was too low at April? Any changes made on the evil on IPs criteria at that moment?

No, limited as yearn finance I think and that's why there are more evil on a lot of IPs. The % is moving slowly and that's good for future, same thing happening in bitcoin too.