This simple exercise is stumping me and it is very frustrating.

I have the following table of info that I want to plot in a column chart (Excel 2010).
Table1.JPG

I need to show sales on the left side of the chart and contribution (percentages) on the right.
Currently, I have the graph below, which I like...I'd like to have the same on the right for the percentages.
Table2.JPG

I've spent over an hour trying to format the secondary axis as a percentage, but it is not working. Any insight? Is the data arranged incorrectly in the table? I've rearranged it several times and am not getting anywhere. I am at the point of diminishing returns. Thank you so much for any help!!!