condition mean min max ZT0-3 35.22645 35.22645 35.22645 ZT4-7 26.5927 26.5927 26.5927 ZT8-11 24.4735 24.4735 24.4735 ZT12-15 24.56305 24.56305 24.56305 ZT16-19 27.88295 27.88295 27.88295 ZT20-23 36.3848 36.3848 36.3848