condition mean min max ZT0-3 22.358999 22.358999 22.358999 ZT4-7 20.1095055 20.1095055 20.1095055 ZT8-11 23.542501 23.542501 23.542501 ZT12-15 27.043358499999997 27.043358499999997 27.043358499999997 ZT16-19 29.889176 29.889176 29.889176 ZT20-23 34.9343005 34.9343005 34.9343005