condition mean min max ZT0-3 4.70531 4.00893 5.963405 ZT4-7 6.3209599999999995 6.3209599999999995 6.3209599999999995 ZT8-11 6.436030000000001 6.436030000000001 6.436030000000001 ZT12-15 6.95598 6.92549 6.98647 ZT16-19 7.050314999999999 7.050314999999999 7.050314999999999 ZT20-23 4.17224 4.17224 4.17224