Per AllanJude's comment in https://reviews.freebsd.org/D24321, the number of contributors should be made consistent, which probably requires crawling over logs and PRs to update it from 2019 data, since the original code was lost. Additionally, the #ports vs. time graph and tables should be updated as well. And this time, the code to do it should be committed to the doc repo so it doesn't get lost in the mists of history *again*. I'm willing to contribute to the effort of writing and testing that code, but I don't think it can be just me, because (for one thing) I have no idea where/how to get started on crawling over Bugzilla PRs.
Maybe relevant: https://news.freshports.org/2020/11/18/how-many-ports-are-there/