condition mean min max ZT0-3 6.296665 6.0176549999999995 6.575675 ZT4-7 5.785715 5.785715 5.785715 ZT8-11 3.1457050000000004 3.1457050000000004 3.1457050000000004 ZT12-15 0 0 0 ZT16-19 4.2047799999999995 4.2047799999999995 4.2047799999999995 ZT20-23 6.500145 6.500145 6.500145