Count number of "Left" in this measure

[EdMbu]

Lost Customers = IF([Total_amount_exclude_vat_]>0&&'All measure'[Last Period Revenue]<=0, "Left", BLANK())

Can someone explain to me how I can count the row number of this measure and filter the number of "Left". this measure is in a measure table. Thanks 

[EdMbu]

Thanks. its work

[lbendlin · Accepted solution]

To count the rows of a table you need to have a table first. 

Create a table variable to SUMMARIZE over the customer IDs. Use ADDCOLUMNS to compute if they left or not. FILTER the result by the ones that left.  Do a COUNTROWS over that result. That's what your measure should return.