condition mean min max ZT0-3 33.14895 14.71535 45.3709 ZT4-7 12.12095 12.12095 12.12095 ZT8-11 15.4628 15.4628 15.4628 ZT12-15 17.144525 16.5514 17.737650000000002 ZT16-19 23.336550000000003 23.336550000000003 23.336550000000003 ZT20-23 45.2713 45.2713 45.2713