condition mean min max ZT0-3 3.400875 2.64841 4.15334 ZT4-7 3.7102899999999996 3.7102899999999996 3.7102899999999996 ZT8-11 9.10304 9.10304 9.10304 ZT12-15 0 0 0 ZT16-19 10.353259999999999 10.353259999999999 10.353259999999999 ZT20-23 5.81029 5.81029 5.81029