Invoice Number - Distinct Count

We are wondering how other Ariba customers are finding the number of invoices processed monthly. We are finding that neither Invoice Count nor Invoice Quantity in SpendViz give us a count of unique invoice numbers for a supplier. Pivot tables in Excel also do not give us a count of only distinct invoice numbers.

In one example we see this in SpendViz:

Supplier A, Invoice 1, Invoice Count 0.88888888889, Invoice Quantity 28

Supplier A, Invoice 1, Invoice Count 0.11111111111, Invoice Quantity 1

In another example we see this is Spend Viz:

Supplier B, Invoice 2, Invoice Count 1, Invoice Quantity 0

Supplier B, Invoice 2, Invoice Count 1, Invoice Quantity 0

In Excel Pivot Table we get:

Supplier C, Invoice 3, Invoice Count 1

Supplier C, Invoice 3, Invoice Count 1

Supplier C, Invoice 3, Invoice Count 1

Obviously in excel it is counting each row for the supplier.

I don't know what SpendViz is doing exactly, I just know it's not giving us the number we are ultimately looking for.

Any help is appreciated.