condition mean min max ZT0-3 0.39956933333333333 0.0 0.766365 ZT4-7 0.2004265 0.2004265 0.2004265 ZT8-11 2.213195 2.213195 2.213195 ZT12-15 2.48095 2.109975 2.851925 ZT16-19 0.793519 0.793519 0.793519 ZT20-23 0.455862 0.455862 0.455862