condition mean min max ZT0-3 0.41796075 0.41796075 0.41796075 ZT4-7 0.75953425 0.75953425 0.75953425 ZT8-11 0.78783775 0.78783775 0.78783775 ZT12-15 0.6037745083333333 0.6037745083333333 0.6037745083333333 ZT16-19 0.503401 0.503401 0.503401 ZT20-23 0.53513025 0.53513025 0.53513025