condition mean min max ZT0-3 8.87805 8.87805 8.87805 ZT4-7 8.635685 8.635685 8.635685 ZT8-11 8.456724999999999 8.456724999999999 8.456724999999999 ZT12-15 9.171305 9.171305 9.171305 ZT16-19 8.466655 8.466655 8.466655 ZT20-23 8.35763 8.35763 8.35763