That does work for the table I showed in my original post.
It does not work, however, if you add the Location as a dimension. I was trying to implement Location as a conditional dimension and allow the client to turn it on and off with a button. Instead of this, I have created two seperate tables with different expressions and put them in a Container. Also added a third table to the container to show them the breakdown by Month.
Overall, I have given the client more information than they requested, but hopefully they can use it to validate the calculations and use it with confidence.