condition mean min max ZT0-3 5.126825 5.126825 5.126825 ZT4-7 4.51664 4.51664 4.51664 ZT8-11 4.60258 4.60258 4.60258 ZT12-15 4.96566 4.96566 4.96566 ZT16-19 5.33791 5.33791 5.33791 ZT20-23 5.02671 5.02671 5.02671