condition mean min max ZT0-3 3.1019099999999997 2.828575 3.3752449999999996 ZT4-7 2.63017 2.63017 2.63017 ZT8-11 3.485575 3.485575 3.485575 ZT12-15 0 0 0 ZT16-19 4.8225 4.8225 4.8225 ZT20-23 3.865475 3.865475 3.865475