condition mean min max ZT0-3 3.9022699999999997 1.8212350000000002 6.30697 ZT4-7 2.0017 2.0017 2.0017 ZT8-11 2.35638 2.35638 2.35638 ZT12-15 1.8635924999999998 1.52227 2.2049149999999997 ZT16-19 1.129751 1.129751 1.129751 ZT20-23 3.179705 3.179705 3.179705