condition mean min max ZT0-3 18.103724999999997 17.04675 19.1607 ZT4-7 19.349899999999998 19.349899999999998 19.349899999999998 ZT8-11 9.650815 9.650815 9.650815 ZT12-15 0 0 0 ZT16-19 11.8945 11.8945 11.8945 ZT20-23 18.726 18.726 18.726