In theory another report could show that if you apply the same filter:
https://download.opensuse.org/report/download?group=project,mirror

But the problem is that current report is limited by 1000 rows and that 'project,mirror' division generates much more around (200 mirrors x 20 projects) for single day. So it probably is not very representative. I must increase the limit or think about adding filter into url.

Until that I have temporarily increased the limit on mirrorcache-eu, so its report will be useful for that (it uses the same DB):
https://mirrorcache-eu.opensuse.org/report/download?group=project,mirror

From what I see most comes from TW iso, then TW repo, then 15.5 updates and repo

Full list of projects is defined at https://download.opensuse.org/app/project