condition mean min max ZT0-3 26.256866666666667 17.8198 30.78725 ZT4-7 16.965899999999998 16.965899999999998 16.965899999999998 ZT8-11 18.2078 18.2078 18.2078 ZT12-15 29.694025 27.559649999999998 31.828400000000002 ZT16-19 30.924149999999997 30.924149999999997 30.924149999999997 ZT20-23 38.7224 38.7224 38.7224