condition mean min max ZT0-3 5.481315 5.481315 5.481315 ZT4-7 3.5395649999999996 3.5395649999999996 3.5395649999999996 ZT8-11 2.90345 2.90345 2.90345 ZT12-15 4.473755 4.473755 4.473755 ZT16-19 5.953985 5.953985 5.953985 ZT20-23 5.831365 5.831365 5.831365