condition mean min max ZT0-3 5.375885 3.6155 7.13627 ZT4-7 0.0 0.0 0.0 ZT8-11 3.67708 3.67708 3.67708 ZT12-15 0 0 0 ZT16-19 3.561735 3.561735 3.561735 ZT20-23 1.77882 1.77882 1.77882