Hello,
it’s seem that rubygems.org has desactivate statistics curves.
So here a little tools for make your own plot.
Gems stat in 3D :
https://dl.dropboxusercontent.com/u/17903299/GEMS.html
for create your own curves, see
https://github.com/raubarede/Ruiby/tree/master/tmp
duplicate the .rb , change constants and run it every days…