condition mean min max ZT0-3 6.491103333333333 5.63507 7.84937 ZT4-7 4.31926 4.31926 4.31926 ZT8-11 6.126995 6.126995 6.126995 ZT12-15 14.600275 13.652149999999999 15.5484 ZT16-19 11.87795 11.87795 11.87795 ZT20-23 10.156695 10.156695 10.156695