condition mean min max ZT0-3 3.5336133333333333 3.0028550000000003 4.28679 ZT4-7 3.27731 3.27731 3.27731 ZT8-11 1.876135 1.876135 1.876135 ZT12-15 2.0569625 1.5875400000000002 2.5263850000000003 ZT16-19 3.2899000000000003 3.2899000000000003 3.2899000000000003 ZT20-23 3.214135 3.214135 3.214135