condition mean min max ZT0-3 29.409472 29.409472 29.409472 ZT4-7 27.3498885 27.3498885 27.3498885 ZT8-11 26.7093105 26.7093105 26.7093105 ZT12-15 34.8393385 34.8393385 34.8393385 ZT16-19 46.456984500000004 46.456984500000004 46.456984500000004 ZT20-23 81.95984 81.95984 81.95984