condition mean min max ZT0-3 14.808034 14.808034 14.808034 ZT4-7 18.004189500000003 18.004189500000003 18.004189500000003 ZT8-11 17.655871 17.655871 17.655871 ZT12-15 16.0377715 16.0377715 16.0377715 ZT16-19 18.383657 18.383657 18.383657 ZT20-23 19.762769 19.762769 19.762769