condition mean min max ZT0-3 3.3504633333333333 2.2651399999999997 4.844 ZT4-7 2.072415 2.072415 2.072415 ZT8-11 0.6798474999999999 0.6798474999999999 0.6798474999999999 ZT12-15 0.66282525 0.600092 0.7255585 ZT16-19 0.466496 0.466496 0.466496 ZT20-23 0.6756325 0.6756325 0.6756325