Backup management

Hi.
I use Adobe Lightroom extensively and have it set up to make weekly backups of it's catalogue. Each backup creates a single folder inside the main backups folder. However, the backups folder can grow unnecessarily large over time and I have to delete some of the older ones.
How would I go about creating a Hazel rule that preserves the latest 10 (or 15, or 20,...) backups and deletes the rest?
If it isn't possible I'll just create a rule that deletes older than x months backups, but I would prefer to use a rule described in the question above.
I use Adobe Lightroom extensively and have it set up to make weekly backups of it's catalogue. Each backup creates a single folder inside the main backups folder. However, the backups folder can grow unnecessarily large over time and I have to delete some of the older ones.
How would I go about creating a Hazel rule that preserves the latest 10 (or 15, or 20,...) backups and deletes the rest?
If it isn't possible I'll just create a rule that deletes older than x months backups, but I would prefer to use a rule described in the question above.