How can I reduce the size of my Capture One Backup folder?

I've been using Capture One for years and have been backing up regularly. I realised today this folder set is about 300GB in sizeand has a bunch of masks from work that is multiple years old.

I don't need the masks or adjustments backed up for longer than 12 months though for the kind of work I do.

To reduce the size, should I go ito these dated folders and delete the ones I don't need or should I unlink them in capture one? What's the best way I should do this? I normally create a new catalog every year and start from fresh so I'm not that far from doing that for 2023.

Any advice would be hugely appreciated.