If you add statistics-enabled="true" to you cache that will do the job.
The change that went in the code meanwhile is to be found on this issue:
However, what you are seeing would probably be a bug. We only wanted to make the container and caches be able to configure statistics independently but this may have slipped in.
Thanks! As a work around I also specified statistics-enabled="true" on our default cache. Since we use that as the base configuration for our programmatically defined caches it gave us the desired results.