Thanks! You're not thick, it's just that this isn't really the best visualization choice for the data since the rings are independent and not hierarchical (like in http://mbostock.github.com/d3/ex/sunburst.html).

You are absolutely right about the scale for the bar charts, oversight on my part which I have fixed now. The adding to 99% is a rounding error (you can see the fully number value by mousing over a bar) - thanks a ton for your feedback!