4Clojure solutions over time

Somebody recently posted in the Clojure subreddit that there had just been over 1 million problems solved on the 4Clojure website. When I saw this I wondered if we could get a graph of the number of solutions solved over time, so I sent an email to the 4Clojure guys asking if they had the data to generate such a graph. The reply:

I don’t think we actually save that anywhere, no. Too bad; that’d be a neat graph.

Checked Wayback machine and there were a bunch of snapshots since 2011. A few curl requests and some grep filtering later I had the counts and could plot a graph with C3.js.