2023-07-15 10:34 859 instances, 29068 communities
2023-07-16 10:34 853 instances, 29468 communities
2023-07-17 10:34 851 instances, 30223 communities
2023-07-18 08:10 858 instances, 30376 communities
2023-07-18 12:05 860 instances, 30294 communities
2023-07-18 18:05 856 instances, 29762 communities
2023-07-19 00:25 852 instances, 29361 communities
2023-07-19 06:04 842 instances, 29956 communities
2023-07-19 12:05 837 instances, 29917 communities
2023-07-19 18:04 830 instances, 29677 communities
2023-07-20 00:14 827 instances, 29677 communities
2023-07-20 06:04 825 instances, 29544 communities
2023-07-20 12:06 812 instances, 28591 communities
2023-07-20 18:04 811 instances, 28559 communities
2023-07-21 00:14 790 instances, 28422 communities
2023-07-21 06:05 786 instances, 27407 communities
2023-07-21 12:05 785 instances, 28522 communities
2023-07-21 18:05 785 instances, 28191 communities
2023-07-22 00:14 778 instances, 27242 communities
2023-07-22 06:05 772 instances, 25492 communities

I was hoping those 5595 spam communities a disgruntled lemmy.world created had finally been deleted, but it's not that.
The data is published about 4 times a day, and there's a bit of variance each day, but not as much as the latest difference.