condition mean min max ZT0-3 1.2930998333333334 0.2207995 1.968755 ZT4-7 0.581417 0.581417 0.581417 ZT8-11 1.0705635 1.0705635 1.0705635 ZT12-15 1.5400725 1.31875 1.7613949999999998 ZT16-19 1.779985 1.779985 1.779985 ZT20-23 2.881125 2.881125 2.881125