Hello,

I have a simple example workbook attached. It contains name, week, and sales. I have calculated:

• % difference of sales from previous week; and
• % of total sales (market share)

What I do want to calculate is % change in market share from previous week. I have attempted to do this in the past, but I think the reason I got stuck is that it requires calculation across(previous period) and down(market share). If someone could please help by showing me how to do this in the attached workbook it would be greatly appreciated.

Regards,

Nathan