condition mean min max ZT0-3 21.21527 5.63436 29.7684 ZT4-7 3.6017850000000005 3.6017850000000005 3.6017850000000005 ZT8-11 5.810829999999999 5.810829999999999 5.810829999999999 ZT12-15 12.052005 6.70766 17.396349999999998 ZT16-19 21.78805 21.78805 21.78805 ZT20-23 36.23565 36.23565 36.23565