In London?...
I'd say the number is under 10%. At least 90% of cyclists do not RLJ.
You may have 60%+ of junctions that have at least one red light jumper though, but that's not the same thing.
I spend a lot of time at junctions, often surrounded by 10 cyclists. It's rare to see more than one, maybe two, go on regardless.
By all means lynch me, but there are several junctions where I'll proceed with caution regardless of the colour of the light.
This one for example -
http://goo.gl/maps/OYRgx (I keep way left)
I don't think that I'm big, special, or clever, but at this junction, and others, you can proceed with 100% certainty that you're not going to have an interaction with a pedestrian or vehicle. I don't need an endorsement, just stating my opinion.
I'm not advocating flying through any junction at speed, that's moronic, but whilst cycling, walking, or driving, there are many many junctions that I don't give a damn about cycles RLJ'ing.
It's the tools that do it here -
http://goo.gl/maps/dhIGI - and places like it which baffle me.
That's all I've got.