Report on User last RDM Version

I searched in "Users" and "Reports" and did a quick check on the forum but couldn't see a way to report the version of RDM last opened by a user. I'd like to track this so I can see quickly my organization is adopting updates that I'm requesting them to install. Essentially, when we validate an upgrade and request users to install it, I need to give them a reasonable amount of time to perform the upgrade before I set the minimal version, and I'd say that's probably right around 80% adoption rate, but I don't see a way to determine their last used version.

Thanks!