condition mean min max ZT0-3 3.73875233325 3.696530868 3.7809737985 ZT4-7 2.254877434 2.142890637 2.366864231 ZT8-11 4.1301144755 3.022118185 5.238110766 ZT12-15 4.98634648725 4.939742816 5.0329501585 ZT16-19 6.99185568475 6.13408059 7.8496307795 ZT20-23 10.97977904625 10.2198718425 11.73968625