Well, as heishe stated, you simply won't find global stats on APM, because most people don't care. The only people that could publish reliable data on the topic are Blizzard, and I have yet to hear if they care.
This is not meant as an insult, but only newbies seem to care about APM/EPM, probably because they see korean pros move their fingers so fast it's almost like you're watching an anime. I have 120 APM myself, and I'm a bronze player. I know other players in Bronze that have way above 250 APM. Similarly, I know a plat player who has the same APM as me.
It's a bit like saying whether a racing car can handle 4k or 6k RPM. Of course it relates, but there are more important factors for the car's performance on the track, of which the pilot's brain is not the least important. I'm not a mechanic, so please excuse any rampant mistakes in my analogy =)
The underlying truth about APM is yes, APM matters, but only once your brain is faster than your fingers, and you'll be low Master league by the time this happens.