condition mean min max ZT0-3 11.533945 11.533945 11.533945 ZT4-7 10.4307345 10.4307345 10.4307345 ZT8-11 10.9660125 10.9660125 10.9660125 ZT12-15 11.924387 11.924387 11.924387 ZT16-19 12.636331 12.636331 12.636331 ZT20-23 11.533945 11.533945 11.533945