condition mean min max ZT0-3 13.920656666666666 6.7544699999999995 18.24105 ZT4-7 6.086845 6.086845 6.086845 ZT8-11 18.33 18.33 18.33 ZT12-15 26.912875 23.6881 30.13765 ZT16-19 23.35655 23.35655 23.35655 ZT20-23 25.98475 25.98475 25.98475