condition mean min max ZT0-3 17.98875 17.98875 17.98875 ZT4-7 17.1203 17.1203 17.1203 ZT8-11 16.39345 16.39345 16.39345 ZT12-15 15.7986 15.7986 15.7986 ZT16-19 21.65035 21.65035 21.65035 ZT20-23 18.403399999999998 18.403399999999998 18.403399999999998