condition mean min max ZT0-3 27.63777778 27.63777778 27.63777778 ZT4-7 23.64 23.64 23.64 ZT8-11 20.37888889 20.37888889 20.37888889 ZT12-15 10.17888889 10.17888889 10.17888889 ZT16-19 9.508888887666666 9.508888887666666 9.508888887666666 ZT20-23 10.499999999 10.499999999 10.499999999