Not sure whether it has been updated since your comment, but the sentence now reads:

    GitHub has had 1125 incidents since March 2016. Over the last 3 months, they've averaged 24 incidents per month

Yes I tweaked it! The number and copy were mismatched and are no longer!

That worst day is likely an overlapping incidents accounting issue; I tried to account for overlapping incidents in another view but probably failed to port it over there.

Should be fixed soon!