Well, the day wasn't a total waste

Searching debt service at FRED I came upon

Households and nonprofit organizations; debt service payments (FSIs), Flow

Whoa, what's that? I asked myself. I think it's debt service in billions, the one I always figure by working backwards from debt service as percent of DPI.

Yup. The yellow line is mine, the way I always figure it. The black line is the one I just found at FRED. I made the black line wide. As you can see, my line runs right down the middle of theirs:

My Debt Service in Billions (yellow) and FRED's in Millions / 1000:  Same same!

Easier to see if you click the graph to enlarge it.