condition mean min max ZT0-3 18.053333333333335 17.5407 18.3277 ZT4-7 20.6449 20.6449 20.6449 ZT8-11 18.845399999999998 18.845399999999998 18.845399999999998 ZT12-15 29.327125000000002 29.0953 29.55895 ZT16-19 19.9989 19.9989 19.9989 ZT20-23 20.243850000000002 20.243850000000002 20.243850000000002