condition mean min max ZT0-3 12.088992 12.088992 12.088992 ZT4-7 11.7316665 11.7316665 11.7316665 ZT8-11 11.753364 11.753364 11.753364 ZT12-15 11.7428435 11.7428435 11.7428435 ZT16-19 14.9452875 14.9452875 14.9452875 ZT20-23 19.5144125 19.5144125 19.5144125