condition mean min max ZT0-3 1.94018 1.94018 1.94018 ZT4-7 0.645648 0.645648 0.645648 ZT8-11 0.5417563333333333 0.5417563333333333 0.5417563333333333 ZT12-15 0.32191800000000004 0.32191800000000004 0.32191800000000004 ZT16-19 1.5598800000000002 1.5598800000000002 1.5598800000000002 ZT20-23 2.39858 2.39858 2.39858