condition mean min max ZT0-3 0.5264861666666667 0.4182745 0.7211785 ZT4-7 0.6371125 0.6371125 0.6371125 ZT8-11 0.326941 0.326941 0.326941 ZT12-15 0.5083092499999999 0.2623235 0.7542949999999999 ZT16-19 0.6552435000000001 0.6552435000000001 0.6552435000000001 ZT20-23 0.737763 0.737763 0.737763