I have a pivot table with two sets of data as follows:

           2011    2012
Slice A      45      20
Slice B      33      28
Slice C      22       2

I am trying to present two pie charts side-by-side, one with the 2011 data and one with the 2012 data. I want the relative size of each pie chart to reflect the totals, i.e. the pie chart with the 2011 data (totalling 100) should be twice the size of the pie chart with the 2012 data (totalling 50).

The 'pie of pie' chart type seems to be closest to what I am looking for but this breaks out data from one slice and presents it in a second diagram so it isn't appropriate here.