condition mean min max ZT0-3 0.868583 0.819928 0.9260999999999999 ZT4-7 2.5374499999999998 2.5374499999999998 2.5374499999999998 ZT8-11 7.02039 7.02039 7.02039 ZT12-15 4.5034525 2.93592 6.070985 ZT16-19 1.76841 1.76841 1.76841 ZT20-23 1.77158 1.77158 1.77158