condition mean min max ZT0-3 3.9898599999999997 3.5574149999999998 4.422305 ZT4-7 3.28716 3.28716 3.28716 ZT8-11 3.461105 3.461105 3.461105 ZT12-15 0 0 0 ZT16-19 3.9260650000000004 3.9260650000000004 3.9260650000000004 ZT20-23 4.43987 4.43987 4.43987