condition mean min max ZT0-3 1.3853365 0.3178695 2.01969 ZT4-7 0.8755695 0.8755695 0.8755695 ZT8-11 1.56079 1.56079 1.56079 ZT12-15 1.5900902500000003 0.9988105 2.1813700000000003 ZT16-19 3.9134349999999998 3.9134349999999998 3.9134349999999998 ZT20-23 4.408665 4.408665 4.408665