Statistics on EAP methods widely used

Hello all, I apologize for the "spam" but I thought that you would be able to give me a couple of pointers on the following. I am trying to find some statistics on what is the most commonly deployed/used EAP method using FreeRadius (or RADIUS in general). There are many claims that, for example, EAP-TLS and EAP-TTLS are most commonly used (and secure) but these are never backed up by any survey/references. Any pointers? Thanks a lot, Panos