condition mean min max ZT0-3 7.835185 7.835185 7.835185 ZT4-7 1.092222 1.092222 1.092222 ZT8-11 12.8941 12.8941 12.8941 ZT12-15 37.15695 37.15695 37.15695 ZT16-19 43.78845 43.78845 43.78845 ZT20-23 25.7594 25.7594 25.7594