condition mean min max ZT0-3 17.655871 17.655871 17.655871 ZT4-7 16.7315755 16.7315755 16.7315755 ZT8-11 22.4254845 22.4254845 22.4254845 ZT12-15 27.4527635 27.4527635 27.4527635 ZT16-19 24.874125 24.874125 24.874125 ZT20-23 23.541526 23.541526 23.541526