Calculated Rows in a Matrix

Hi all

I am using a Matrix as a workaround to get a bar chart with a data table underneath (as per Excel built in chart data tables).

What the data set will produce is a chart that has three series on the rows (This Week, Previous Week, Previous Year), and seven columns (one for each day of the week). I would also like two additional rows in the matrix that follow these expressions, you will see from the image I have already added these non-grouped rows.

Additional Row 1 = ('This Week' / 'Previous Week') - 1

Additional Row 2 = ('This Week' / 'Previous Year') - 1

Here is the structure of the Matrix.

Here is the dataset I am working with.

Please let me know if you need anymore detail.