condition mean min max ZT0-3 2.8735524999999997 2.55675 3.190355 ZT4-7 1.554055 1.554055 1.554055 ZT8-11 1.647475 1.647475 1.647475 ZT12-15 0 0 0 ZT16-19 1.89908 1.89908 1.89908 ZT20-23 3.048445 3.048445 3.048445