Well, I know that 80% is the cut off for "normal" and I saw one thing that said 76% and one that said 78%...of course, who knows if what I saw was actually related to that 80% number?? The tech. made me redo the last test after resting a while and then made a gesture and sound that said to ME "Ok, I guess that's the best she can do." It was like playing charades! lol