You could use Size() and a Las() function as a filter and get the same output.
See the attached updated workbook.
Size() is a great choice for unique counts across data sources if you can create a view where every unique row is displayed. In this case, I use Last() as a filter to hide the other rows except the last one and each of the table calculations are also calculated for every row but only shown in the last row. Note that the customer num field has been hidden by turning the field off with the "show header" disabled.
Thanks for sharing this Patrick ! (Yes this is the one which I found somewhere , probably in Jonthan's post )
I just shared the another way ...of doing the same.
Thanks again & Regards,