condition mean min max ZT0-3 6.9186250000000005 6.9186250000000005 6.9186250000000005 ZT4-7 2.7217700000000002 2.7217700000000002 2.7217700000000002 ZT8-11 1.990435 1.990435 1.990435 ZT12-15 2.2805999999999997 2.2805999999999997 2.2805999999999997 ZT16-19 12.276299999999999 12.276299999999999 12.276299999999999 ZT20-23 8.60512 8.60512 8.60512