Just a thought.

You show pie charts of number of hosts by OS and by processor manufacturer. These charts might also be interesting if they showed total cobblestones by OS and by processor.

I wonder, for example, whether the proportional split between Win and Linux is the same by host and by cobblestone or if there is a marked difference in the performance of the average host by OS.

It is quite possible that there is no difference, in which case the two extra charts would be completely uninteresting!