condition mean min max ZT0-3 6.21654986675 6.1183256495 6.314774084 ZT4-7 6.24695728825 5.9742532865 6.51966129 ZT8-11 6.2814681735 5.958106908 6.6048294389999995 ZT12-15 3.626863437 2.7994951335000002 4.4542317405 ZT16-19 1.1558129350000002 0.96118236 1.35044351 ZT20-23 2.5210313380000002 0.989060088 4.053002588