How to Calculate Median Core Product Actions Before User Upgrades

Hi there, I'm trying to keep track of a funnel:

I want to know the median count of the Core Product Action before a user Upgrades. Does anyone know how I best can do this? I've been trying out JQL, but with limited success and I can't find it in the dashboarding option. I'm hoping I don't have to migrate all my data to a datawarehouse to run some queries on it.... Any thoughts?