Showing values as a percentage in a bar chart - but keeping scale as the values

I currently have a set of data the is shown in a column chart. At the moment, the 'y' axis has the scale set to the values and each bar is shown as the value itself.

Is there anyway of showing the figure on the bar as a percentage of the total for that bit, whilst keeing the 'y' axis as the values?

Hope this makes sense??

Please note this is for a column chart, not bar chart