condition mean min max ZT0-3 20.789833333333334 19.54495 22.33915 ZT4-7 14.5972 14.5972 14.5972 ZT8-11 12.92455 12.92455 12.92455 ZT12-15 19.64255 19.0594 20.2257 ZT16-19 16.34705 16.34705 16.34705 ZT20-23 22.86075 22.86075 22.86075