Hi Forum and a good morning from Germany!

I am pretty new to this advanced excel functionality but I am going to love it. So I am not sure if my request is for PowerPivot or PowerQuery. My data source file is attaced.

I am trying to evaluate how many orders each customer placed in a certain time period. One invoice date equals one order. In my PowerPivot I have already made new colums for Month and Year based on the Invoice date column. So in my simple mind I thought that I would need an additional column which counts the amount of Invoice dates. And later on I can use this column to spread out the data in a pivot table. I like the example below.

                     #Orders 

Customer       2018      2019      2020

Customer A         12         10         13

But I am struggeling with the formula because I am just to new to DAX formulars and where should I do it in PowerPivot or PowerQuery? I hope I could explain my problem good enough and the attached example file is OK.

Best regards and many thanks in advanced
Michael