condition mean min max ZT0-3 0.37335050000000003 0.37335050000000003 0.37335050000000003 ZT4-7 0.394381 0.394381 0.394381 ZT8-11 0.2776305 0.2776305 0.2776305 ZT12-15 0.2490561 0.2490561 0.2490561 ZT16-19 0.30649 0.30649 0.30649 ZT20-23 0.34886799999999996 0.34886799999999996 0.34886799999999996