It would be nice to be able to see how many of each cache type there is in an area. This could be represented as a histogram. Instead of the Caches per Area being broken down by the different sub areas, the histogram would show cache types.
The information is currently available if someone does the work and makes several filtered caches per area requests. It seems nice to know what percentage of the caches are Traditionals versus Unknown. Also it would be nice to be able to compare regions. Does Germany have a different distribution of caches than Michigan?
Finds per Area also seems a candidate for this extension.