I would like to create a chart in which one large circle represents the total
amount of something. That is, it represents 100%. I'd like to then have one
or more circles inside it to represent subset(s) of the large circle. For
example, the large circle might be all people in a zip code. The small circle
could be female residents, or left-handed people. It would be neat to be able
to have more than one subset circle, but I'd settle for one for now.