How to Average a sum of distinct values in Webi

Hi all,

I'm trying to get an average of a set of monthly values. However the monthly values are also a calculated field that I need to get a count of unique Unit Numbers per month but then average that value by month. NOTE: I am using SAP BW query as my datasource and do not have access to use a universe.

I have a sample dataset below to demonstrate what I'm looking for.

Above is my raw data set coming into Webi from my data source.

What I want to do is get the unit count of unique "Unit No" values by month. Like this:

But then what I want to actually display in my report is the average of those values by month like this:

Any assistance is appreciated. Thanks!