condition mean min max ZT0-3 1.689975 1.689975 1.689975 ZT4-7 0.625645 0.625645 0.625645 ZT8-11 1.0938915 1.0938915 1.0938915 ZT12-15 2.2295350000000003 2.2295350000000003 2.2295350000000003 ZT16-19 3.125025 3.125025 3.125025 ZT20-23 2.39069 2.39069 2.39069