Thanks for that Mayan,
Problem I'm having is that when I try using the table calculation options, the percentages do not add up to 100%?
I have used the option to express each value as a percentage of the total row but it doesn't seem to be working .... any ideas?
Can you provide an example workbook, or a screen shot of your Viz?
You most likely need to change the Compute Using to Pane Down. (I am assuming it has been defaulted to Table Down). If it isn't that, then you might need to change what the Window Calc is partitioning on. But I can't know that without seeing the ViZ Level of Detail.