I've been running a script for the last few months which grabs the current size of the ipv4 and ipv6 FIBs for a full routing table, once a day, and writes it to an RRA.
here's the results: http://imgur.com/a/iJfPT That chart with the green is actually drawing both v4 and v6 on the same chart. That almost impossible to see blue line at the bottom of the chart? That's the v6. For comparison, a standalone v6 chart is the second image.
