One single graft grows how many hair at most?

A hair graft produces 1,2 or 3 hairs. "Follicular units" is the term given to the natural groupings of hairs in the scalp - and these follicular units contain 1-3 hairs.  They generate 1-3 hairs

Of course the answer to that question should bee as many hairs that the graft contain, 1,2 3 or 4 hairs. If everything is done correctly, we expect 100% of the transplanted hair to grow but from a practical point of view, I generally expect over 90%, may be 99%. We never really can count the number accurately unless we did less than 10, then we would know for sure