condition mean min max ZT0-3 21.421091095833333 16.744022496666666 26.098159695 ZT4-7 19.4947845 19.43260016 19.55696884 ZT8-11 22.05672299 20.737035276666667 23.376410703333335 ZT12-15 18.231311525000002 16.917638033333333 19.54498501666667 ZT16-19 16.542478170000003 15.911503510000001 17.173452830000002 ZT20-23 15.641963220000001 15.534597669999998 15.749328770000002