condition mean min max ZT0-3 3.8482149999999997 3.8482149999999997 3.8482149999999997 ZT4-7 2.80886 2.80886 2.80886 ZT8-11 2.903485 2.903485 2.903485 ZT12-15 3.799535 3.799535 3.799535 ZT16-19 3.68985 3.68985 3.68985 ZT20-23 3.2224899999999996 3.2224899999999996 3.2224899999999996