Here’s the action at New Savanna over the last year:
Notice the large increases in August and September of last year and in March through May of this year along with a more modest increase in December.
Now look at the all-time action:
There’s that big jump in 2017 and something similar this past year. I have no idea what’s going on in either case. In particular, in the current case, there doesn’t seem to be a big increase in interest in current posting, at least nothing I could see simply by eye-balling the hit rate. Whatever’s happening would seem to be more widely distributed. As I recall, it was like that for 2017 as well.
Here's a post from November 2017 where I note that older action, and one from January 2017, nearer the beginning of that older rise.
FWIW, here's the top 10 posts for the last year: