condition mean min max ZT0-3 19.867165 19.867165 19.867165 ZT4-7 22.57119 22.57119 22.57119 ZT8-11 28.597942 28.597942 28.597942 ZT12-15 34.2018015 34.2018015 34.2018015 ZT16-19 31.5724345 31.5724345 31.5724345 ZT20-23 24.074579999999997 24.074579999999997 24.074579999999997