condition mean min max ZT0-3 19.716525 18.842 20.591050000000003 ZT4-7 14.10725 14.10725 14.10725 ZT8-11 29.81375 29.81375 29.81375 ZT12-15 0 0 0 ZT16-19 33.3792 33.3792 33.3792 ZT20-23 28.57 28.57 28.57