condition mean min max ZT0-3 0.33753000000000005 0.33753000000000005 0.33753000000000005 ZT4-7 0.543805 0.543805 0.543805 ZT8-11 6.0916049999999995 6.0916049999999995 6.0916049999999995 ZT12-15 4.041345 4.041345 4.041345 ZT16-19 5.998076666666667 5.998076666666667 5.998076666666667 ZT20-23 2.65895 2.65895 2.65895