condition mean min max ZT0-3 9.065985088583332 7.764164880666667 10.367805296499998 ZT4-7 8.467232811166667 7.493653472666667 9.440812149666666 ZT8-11 9.058291677166668 9.020573468 9.096009886333334 ZT12-15 7.629323847166667 7.500985047666667 7.757662646666666 ZT16-19 10.1462505085 10.046432033 10.246068984 ZT20-23 11.481307594499999 10.288795191 12.673819997999999