condition mean min max ZT0-3 33.66421244583333 31.691071826666665 35.637353065 ZT4-7 29.592536393333333 27.36871477 31.816358016666666 ZT8-11 30.664748445 29.408353703333333 31.921143186666665 ZT12-15 28.01874641 27.09105457 28.94643825 ZT16-19 24.404625529999997 21.87854349 26.93070757 ZT20-23 23.224792100000002 22.88267647 23.56690773