variance between columns in a matrix

Hi kcantor Thank you very much for the guidance.

So far I was not sure how to create a dimension table, but finally I managed to create them,

I started by creating the table, and then assigning a dimension to the year as shown below:

. I started by establishing a values  on the following format and also created a timestamp to define a year, as that is the only measure I need.

Can you please confirm how to create the relationship between both tables?

Now, when it comes to create the variance on the main table, I am not sure what sort of code should I follow, I tried yours but I am getting the following errorr on triying to display last year sales

I am creating a Matrix table to show the information, not sure what I am missing here.

Thank you very much!!!