Display percentage on line/area graph

Hello:

Thanks for helping me out. I am trying to display percentage on my visualization over time. Specifically, I want a percentage calculated by (count of hits by one filter)/ (count of hits by another filter), and then display their percentage on the y axis, I could not seem to find a way on kibana now. any hints would be appreciated, Thanks.

Kibana currently doesn't handle this use case, but Timelion does.