condition mean min max ZT0-3 13.782683333333333 6.6385749999999994 26.33745 ZT4-7 17.823 17.823 17.823 ZT8-11 6.565805000000001 6.565805000000001 6.565805000000001 ZT12-15 14.523125 14.00655 15.0397 ZT16-19 10.70811 10.70811 10.70811 ZT20-23 7.734 7.734 7.734