condition mean min max ZT0-3 8.447890000000001 8.447890000000001 8.447890000000001 ZT4-7 3.81859 3.81859 3.81859 ZT8-11 8.4915 8.4915 8.4915 ZT12-15 9.45935 9.45935 9.45935 ZT16-19 11.527493333333332 11.527493333333332 11.527493333333332 ZT20-23 11.02746 11.02746 11.02746