condition mean min max ZT0-3 12.867364 12.867364 12.867364 ZT4-7 14.869223999999999 14.869223999999999 14.869223999999999 ZT8-11 20.578391 20.578391 20.578391 ZT12-15 15.8774245 15.8774245 15.8774245 ZT16-19 21.744095 21.744095 21.744095 ZT20-23 15.378718 15.378718 15.378718