condition mean min max ZT0-3 3.907005 1.9314 7.628045 ZT4-7 2.0334649999999996 2.0334649999999996 2.0334649999999996 ZT8-11 1.0335525 1.0335525 1.0335525 ZT12-15 1.7211262500000002 0.9693575 2.4728950000000003 ZT16-19 0.830661 0.830661 0.830661 ZT20-23 1.5289199999999998 1.5289199999999998 1.5289199999999998