6'6" This poll will not get the nice bell curve if it throws the small and (also) the tall in one heap.
Ehh, if the censoring of the tails was really a problem, we would see much larger numbers for those bins.
I'm actually astonished that they results have been so uniform. While this is in no way a random sample, the size is large enough to expect to see normality, if that is the underlying distribution.
Could be a bin size problem, but that doesn't seem to be able to explain it. And I can't imagine height to actually be uniformly distributed...