Report - Can I add freespace percentage?

Hi,

I'd like to create a custom report that contains all volumes with a freespace percentage less than XX%. I've copied and modified the Disk Volumes Basic report but cannot figure out how to insert\configure a percentage.

Is there a way of doing this without creating the report outside of PatchManager? I could go straight at the database and use SQL Reporting, etc, but I'm trying to use the tools native to the product.

Thanks

Rick