condition mean min max ZT0-3 1.02734775 1.02734775 1.02734775 ZT4-7 0.6673825 0.6673825 0.6673825 ZT8-11 0.8284825 0.8284825 0.8284825 ZT12-15 0.80521825 0.80521825 0.80521825 ZT16-19 0.8421175 0.8421175 0.8421175 ZT20-23 1.2599204166666667 1.2599204166666667 1.2599204166666667