condition mean min max ZT0-3 2.220255 2.061155 2.30381 ZT4-7 1.93389 1.93389 1.93389 ZT8-11 1.7267100000000002 1.7267100000000002 1.7267100000000002 ZT12-15 2.1433202500000004 1.727405 2.5592355 ZT16-19 4.13706 4.13706 4.13706 ZT20-23 1.5598795 1.5598795 1.5598795