condition mean min max ZT0-3 38.453475 36.088049999999996 40.8189 ZT4-7 9.94361 9.94361 9.94361 ZT8-11 3.318915 3.318915 3.318915 ZT12-15 0 0 0 ZT16-19 14.06165 14.06165 14.06165 ZT20-23 18.781950000000002 18.781950000000002 18.781950000000002