condition mean min max ZT0-3 0.22679116666666665 0.17407899999999998 0.272588 ZT4-7 0.39674149999999997 0.39674149999999997 0.39674149999999997 ZT8-11 1.024659 1.024659 1.024659 ZT12-15 2.0790575000000002 1.783865 2.37425 ZT16-19 0.8451825 0.8451825 0.8451825 ZT20-23 0.6027685 0.6027685 0.6027685