Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
So if Stealth Rock is used on 11.7% of pokemon, it is used on 70.2% of teams, assuming no two pokemon have it on a single team? I can't decide if that number is surprisingly high or low. :P I guess I would have expected more like 80% or so.