condition mean min max ZT0-3 18.62265081 18.17070695 19.07459467 ZT4-7 16.445920835000003 14.680194263333334 18.211647406666668 ZT8-11 15.97042107 15.822472313333334 16.118369826666665 ZT12-15 20.03245468 19.543132160000003 20.5217772 ZT16-19 22.768038224999998 21.09238514 24.44369131 ZT20-23 18.861344136666666 18.082293963333335 19.640394309999998