condition mean min max ZT0-3 15.076275 13.60455 16.548000000000002 ZT4-7 10.503499999999999 10.503499999999999 10.503499999999999 ZT8-11 6.78779 6.78779 6.78779 ZT12-15 0 0 0 ZT16-19 9.424985 9.424985 9.424985 ZT20-23 12.69075 12.69075 12.69075