They have basically carved out the book and segmented by credit...

They have basically carved out the book and segmented by credit risk scores and then tranched the various parts that they have packaged up as ABS. Each tranche reflects a credit rating and level of risk associated witj the underlying assets in the book. You can see the weightings for each component and the cost assigned to each component. Obviously the higher credit rating the lower the spread to reflect the associated risks. This then reflects the overall funding cost of the transaction. I’m not sure if that explains what you are after?