Discount Percent 1

Hello Gurus!

I am using Vendor discount (OBXU) and it is working OK, but my customer is requiring a report where the percentage of discount could be seen.

I have found a field in fbl1n which name is "Discount Percent 1", but it is empty for a payment which has 4% of discount, my question is....Where could I find the porcentage of discount of payment in a vendor invoice to read it and show it in a report?

Best regards

Alex