condition mean min max ZT0-3 1.93577149075 1.498977604 2.3725653775 ZT4-7 2.5460130912500003 2.5105687015000004 2.581457481 ZT8-11 4.0750094605000005 3.5969676274999998 4.5530512935 ZT12-15 3.37347262625 2.881184713 3.8657605395 ZT16-19 4.839350302250001 4.5233029855 5.155397619 ZT20-23 5.25821159525 4.8361793895 5.680243801