condition mean min max ZT0-3 8.99238 8.99238 8.99238 ZT4-7 3.034525 3.034525 3.034525 ZT8-11 5.121435 5.121435 5.121435 ZT12-15 49.80845 49.80845 49.80845 ZT16-19 59.15965 59.15965 59.15965 ZT20-23 27.4362 27.4362 27.4362