There are a couple of ways you can track patreon development / income over time. You can see on patreon when they've posted / created their account. That gives an indication, but they can delete posts and if they've done multiple projects then the account creation date doesn't help as much. Then there's a site that tracks patreon info over time, cost and subscribers in particular. It's separate from patreon, and since creators can hide some info on patreon it isn't always 100% accurate. Here's
You must be registered to see the links
's page there.
So the info is out there, but not compiled (and would be pretty hard to do since that requires looking at each project and manually marking when projects start and end and such.)