condition mean min max ZT0-3 0.9934276666666667 0.3721915 2.09357 ZT4-7 1.233895 1.233895 1.233895 ZT8-11 0.5110414999999999 0.5110414999999999 0.5110414999999999 ZT12-15 0.66366275 0.283234 1.0440915 ZT16-19 0.4814755 0.4814755 0.4814755 ZT20-23 0.8173665 0.8173665 0.8173665