condition mean min max ZT0-3 26.702483333333333 12.4281 37.48495 ZT4-7 11.052299999999999 11.052299999999999 11.052299999999999 ZT8-11 11.27687 11.27687 11.27687 ZT12-15 18.505200000000002 13.405850000000001 23.604550000000003 ZT16-19 27.773850000000003 27.773850000000003 27.773850000000003 ZT20-23 32.6165 32.6165 32.6165