condition mean min max ZT0-3 18.127395299999996 17.493725899999998 18.7610647 ZT4-7 14.7774917625 13.796559925 15.7584236 ZT8-11 13.7252929925 13.50314763 13.947438355 ZT12-15 9.86566825625 6.9755541895 12.755782323 ZT16-19 10.56271425125 10.09798138 11.0274471225 ZT20-23 18.0743572875 16.95318735 19.195527225