condition mean min max ZT0-3 4.575683333333333 1.846365 6.21826 ZT4-7 1.58662 1.58662 1.58662 ZT8-11 3.090415 3.090415 3.090415 ZT12-15 5.336304999999999 5.238515 5.434095 ZT16-19 7.320125 7.320125 7.320125 ZT20-23 9.869985 9.869985 9.869985