condition mean min max ZT0-3 131.3487 131.3487 131.3487 ZT4-7 32.4628425 32.4628425 32.4628425 ZT8-11 17.536538999999998 17.536538999999998 17.536538999999998 ZT12-15 21.327978 21.327978 21.327978 ZT16-19 18.898782 18.898782 18.898782 ZT20-23 24.770343 24.770343 24.770343