condition mean min max ZT0-3 25.477325 24.40775 26.5469 ZT4-7 12.7128 12.7128 12.7128 ZT8-11 9.992875 9.992875 9.992875 ZT12-15 0 0 0 ZT16-19 35.30025 35.30025 35.30025 ZT20-23 32.51965 32.51965 32.51965