Understanding PBS garbage notification

I am trying to understand the message I get daily from PBS following garbage cleanup:

Datastore: proxmox-backup
Task ID: UPID:fluffles-pbs:000002A6:000009B8:0000004D:674E9050:garbage_collectionroxmox\x2dbackup:root@pam:
Index file count: 896
Removed garbage: 732.203 MiB
Removed chunks: 693
Removed bad chunks: 0
Leftover bad chunks: 0
Pending removals: 33.209 GiB (in 24965 chunks)
Original Data usage: 1.918 TiB
On-Disk usage: 0 B...

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