Number of DPA Licenses in use in DPA 6

Does anybody know a way to find out how many DPA licenses are spare against the number of actual licenses bought in DPA 6?

i.e.  Number of purchased backup licenses - backup clients = spare

I had a report created by Elvin called -Custom- DPA License Details V2 which worked well in version 5.8.5, but I have migrated that over to version 6 and now find it's not working, and can't findwhat I need to change to get it to work again.  Attached screenshot is the output I get from the report.

Can anybody help me get this working again?