How to make a concentric circle graph with smaller percentages on outside rings

[riocielo]

I've been asked to create a graph like the one shown here (but with different numbers):

In the past I've created concentric circle graphs, but this one has me stumped. As you can see the smaller percentages are on the outside rings on the largest number. I'm assuming it has maybe do with the relative width of the visible ring? Any ideas on how I'd set this up? Thanks in advance for your help.

[Monika Gause]

Try processing or d3.js to generate this kind of stuff.