condition mean min max ZT0-3 1.2694649999999998 1.2694649999999998 1.2694649999999998 ZT4-7 0.4771475 0.4771475 0.4771475 ZT8-11 0.23077 0.23077 0.23077 ZT12-15 1.089952 1.089952 1.089952 ZT16-19 3.4802 3.4802 3.4802 ZT20-23 2.362265 2.362265 2.362265