condition mean min max ZT0-3 3.344215 2.5901050000000003 3.847525 ZT4-7 1.65245 1.65245 1.65245 ZT8-11 1.3642905 1.3642905 1.3642905 ZT12-15 3.8362049999999996 3.419825 4.252585 ZT16-19 4.678535 4.678535 4.678535 ZT20-23 5.08596 5.08596 5.08596