condition mean min max ZT0-3 31.83475 31.83475 31.83475 ZT4-7 22.47735 22.47735 22.47735 ZT8-11 24.3084 24.3084 24.3084 ZT12-15 31.81125 31.81125 31.81125 ZT16-19 26.6174 26.6174 26.6174 ZT20-23 35.6342 35.6342 35.6342