This is based on 2009 numbers. As far as I've been able to find, 2009 is the latest there is data available on the combined AGI of the top 1%.
I originally used circles, which I thought looked better, you can see that version here. Then I received some feedback from a couple of people that it might be better to use bars because the perception of accuracy might be better due to what happens to the area occupied by the circles when scaling down. After much consideration I agreed and made the change.