condition mean min max ZT0-3 2.8176316666666663 2.375025 3.1746299999999996 ZT4-7 2.5994650000000004 2.5994650000000004 2.5994650000000004 ZT8-11 2.83685 2.83685 2.83685 ZT12-15 6.17645 6.1063600000000005 6.2465399999999995 ZT16-19 5.04674 5.04674 5.04674 ZT20-23 4.583965 4.583965 4.583965