Resource Schedule Load Graph

What causes capacity to show in the Shop Load Graph? In there I can see a lot of capacity in the past, with 0 actual load. I would like this past capacity to go away, so our graph only shows future capacity and load. I ran the process 690 to create/fix the ShopCap Capacity totals. This seemed to remove some of the oldest capacity, but I still see some in there for last month that I don’t need.