condition mean min max ZT0-3 0.92735795075 0.871634956 0.9830809455 ZT4-7 3.570294742 1.9195796695 5.2210098145 ZT8-11 9.240112638 7.199939013 11.280286263 ZT12-15 17.3152896 16.77395094 17.85662826 ZT16-19 18.3854370225 17.50241036 19.268463685 ZT20-23 30.080234214999997 25.096154615 35.064313815