Difference between Scan and Scan History

Running commands

```
git-secrets —scan -r
git-secrets —scan-history
```

If I then SED, sort & uniq on the containing filenames I get a lot more results for the scan of the current version of the repo than I do for a history scan.

I was expecting the latter to be a super set of the former.

Am I missing something in how I should expect them to work ?

Thanks