condition mean min max ZT0-3 3.1442075 2.220515 4.0679 ZT4-7 11.08738 11.08738 11.08738 ZT8-11 10.523585 10.523585 10.523585 ZT12-15 0 0 0 ZT16-19 6.551465 6.551465 6.551465 ZT20-23 6.274145 6.274145 6.274145