condition mean min max ZT0-3 17.218875 15.3552 19.08255 ZT4-7 10.954965 10.954965 10.954965 ZT8-11 6.714729999999999 6.714729999999999 6.714729999999999 ZT12-15 0 0 0 ZT16-19 8.992775 8.992775 8.992775 ZT20-23 10.3017 10.3017 10.3017