What is the best way to visualize this request?

[Marisa1]

Hello, 

I have a request from our team to show percent of calls we received by call creation week pivoted by when our mail dropped so we could see what percent of calls came from which drop week of mail. We call this our call spillover report. I am having trouble visualizing this as clearly as possible. With more drop weeks added the report, the more hectic it gets. 

Any thoughts? Here is what we have settled on for now below: