Grangeh,
I don't think there is a average helium concentration level per say but I do remember seeing a plotted graph with all the helium concentrations from wells that were drilled. The majority of the weels were way below the 4% mark. It may have been in one of CTP's previous announcements. I will try to find it again and post it here later in the day. Unless, someone beats me to it.
Cheers
