condition mean min max ZT0-3 19.719883333333335 12.15455 24.60845 ZT4-7 14.32175 14.32175 14.32175 ZT8-11 12.341899999999999 12.341899999999999 12.341899999999999 ZT12-15 17.088475000000003 13.86675 20.310200000000002 ZT16-19 18.996000000000002 18.996000000000002 18.996000000000002 ZT20-23 25.080199999999998 25.080199999999998 25.080199999999998