condition mean min max ZT0-3 3.375839045 3.257545626 3.4941324639999998 ZT4-7 1.2852414010000002 1.2645379655000002 1.3059448365000002 ZT8-11 2.59107354075 2.0509834675 3.131163614 ZT12-15 3.37119806525 3.1260382535 3.6163578770000004 ZT16-19 2.3858139675 2.214488577 2.5571393579999997 ZT20-23 4.1228523205 3.8775107130000004 4.368193928