condition mean min max ZT0-3 23.219459 23.219459 23.219459 ZT4-7 22.1585605 22.1585605 22.1585605 ZT8-11 21.743201499999998 21.743201499999998 21.743201499999998 ZT12-15 20.2690425 20.2690425 20.2690425 ZT16-19 22.095256499999998 22.095256499999998 22.095256499999998 ZT20-23 25.490693999999998 25.490693999999998 25.490693999999998