condition mean min max ZT0-3 1.2738045 0.139139 2.0588 ZT4-7 0.4221296 0.4221296 0.4221296 ZT8-11 0.679837 0.679837 0.679837 ZT12-15 1.20864725 0.8878159999999999 1.5294785000000002 ZT16-19 2.786555 2.786555 2.786555 ZT20-23 2.2513750000000003 2.2513750000000003 2.2513750000000003