condition mean min max ZT0-3 1.7899874999999998 1.191545 2.3884299999999996 ZT4-7 3.01965 3.01965 3.01965 ZT8-11 2.9852100000000004 2.9852100000000004 2.9852100000000004 ZT12-15 0 0 0 ZT16-19 2.345965 2.345965 2.345965 ZT20-23 4.122765 4.122765 4.122765