condition mean min max ZT0-3 1.6606681666666667 0.3996745 2.697255 ZT4-7 0.3039085 0.3039085 0.3039085 ZT8-11 0.313543 0.313543 0.313543 ZT12-15 0.41294600000000004 0.4123315 0.4135605 ZT16-19 0.3740965 0.3740965 0.3740965 ZT20-23 1.345425 1.345425 1.345425