condition mean min max ZT0-3 3.1656600089999998 1.3604884240000001 4.970831594 ZT4-7 7.601799195 5.609398122 9.594200268 ZT8-11 15.7434049125 13.38579416 18.101015665000002 ZT12-15 18.216416182499998 16.448627199999997 19.984205165 ZT16-19 15.1031447875 12.609494399999999 17.596795175 ZT20-23 12.5918021825 12.235787779999999 12.947816585000002