condition mean min max ZT0-3 1.6130725 1.23831 1.987835 ZT4-7 2.067875 2.067875 2.067875 ZT8-11 3.082395 3.082395 3.082395 ZT12-15 0 0 0 ZT16-19 3.928215 3.928215 3.928215 ZT20-23 3.31736 3.31736 3.31736