condition mean min max ZT0-3 0.5913338333333333 0.3520295 0.8580165 ZT4-7 0.2006675 0.2006675 0.2006675 ZT8-11 0.314272 0.314272 0.314272 ZT12-15 0.456233 0.364362 0.548104 ZT16-19 0.6968065 0.6968065 0.6968065 ZT20-23 0.709774 0.709774 0.709774