condition mean min max ZT0-3 15.683233333333334 13.68035 16.71425 ZT4-7 14.51525 14.51525 14.51525 ZT8-11 23.39135 23.39135 23.39135 ZT12-15 33.456599999999995 30.4754 36.437799999999996 ZT16-19 24.226599999999998 24.226599999999998 24.226599999999998 ZT20-23 17.58825 17.58825 17.58825