The Statistics -> Overview gives some nice information on the caches hidden per country.
Unfortunately, the Caches per DT section currently only lets you filter on Traditional, Multi and Unknown caches.
It would be nice to be able to filter on all cache types. A nice way of implementing this would IMO be the way it is done in the Profile Stats, tab Finds, section Difficulty / Terrain chart. Maybe with a dropdown box instead of click-to-change.
Come to think of it, it would be nice to have more cache types in that particular section as well.