Show values as percent of a bucket

I'm trying to create a sales pipeline chart that will show me, per campaing, the percent conversion of each stage based on the audience of each campaing. For example, my index writes the following data per campaign:
Sent - 220
Opened - 110
Replyed - 50

I'd like Kibana to show:
Sent - 100% (=220/220)
Opened - 50% (=110/220)
Replyed - 22.7% (=50/220)

I have created a line chart, in which each line represents one campaign. The y-axis represents the sum of users in each pipeline stage and the x-axis is a terms aggregation on each stage, as exemplified in the attached image.

Is it possible to convert this chart to percentages based on the first bucket terms aggregation? If so, could anyone point me in the right direction? (I know how to do this kind of thing in timelion or visual builder, but unfortunately my x-axis is not time-based). I'm using Kibana 7.3.

Thanks in advance.

The only way to do this is with Timelion and Visual Builder. It's not possible with the current aggregations available in the Line Chart.

Thanks for the reply, Marius.