Reduce Volume Reserve

I have a total of 30.34TB of storage.  Of that, 25.36TB is the Volume reserve.  I'm not talking the Snapshot reserve.  Is it possible to reduce this Volume reserve to open up storage space to create volumes or is the volume reserve tied to the current Volumes in use?

If it is possible to reduce the Volume reserve, where to do I click....?

I am on V7.1.8 (R414953) firmware

Thanks