condition mean min max ZT0-3 39.518205 39.518205 39.518205 ZT4-7 35.067150999999996 35.067150999999996 35.067150999999996 ZT8-11 33.0945475 33.0945475 33.0945475 ZT12-15 35.228798999999995 35.228798999999995 35.228798999999995 ZT16-19 28.89734 28.89734 28.89734 ZT20-23 28.9252615 28.9252615 28.9252615