condition mean min max ZT0-3 2.28731187125 1.3109196785 3.2637040639999997 ZT4-7 1.47736302325 1.196338827 1.7583872194999999 ZT8-11 3.07738888075 2.4119671795 3.742810582 ZT12-15 3.0521101149999996 2.9821123725 3.1221078574999996 ZT16-19 1.4117541105 1.335756739 1.487751482 ZT20-23 0.82881026225 0.7032849475 0.9543355769999999