Any question that totals to 100% gets a graphic representation in the form of a pie chart.
I tried to change the code to make it possible to choose a bar chart instead.
I did this because the pie chart is terrible to intepret when it depicts more than 3 variables. It sure looks nice, but it does not convey information in a nice manner: it flabbergasts.
(This link tells it much better than I ever could:
http://www.perceptualedge.com/articles/08-21-07.pdf)