Counter for Template usage on Multisite?

Greetings!

I am looking for a plugin that "tells" me, which of the templates installed in my WPMU are used and how often!

In my blognetwork I have several themes, that I want to replace by other templates, those that are not looking nice, are just outdated or not used in my Blog Community.
https://premium.wpmudev.org/forums/#
Does anyone know a plugin that helps me this way? As I have to much users having blogs on my site as that I could do this manually.

Thanks for your ideas and experiences!