condition mean min max ZT0-3 20.700523 20.700523 20.700523 ZT4-7 30.1657015 30.1657015 30.1657015 ZT8-11 31.346775 31.346775 31.346775 ZT12-15 29.7929755 29.7929755 29.7929755 ZT16-19 33.963986500000004 33.963986500000004 33.963986500000004 ZT20-23 26.1630955 26.1630955 26.1630955