condition mean min max ZT0-3 9.131275 9.131275 9.131275 ZT4-7 10.928730999999999 10.928730999999999 10.928730999999999 ZT8-11 8.8563865 8.8563865 8.8563865 ZT12-15 9.887738 9.887738 9.887738 ZT16-19 9.508328 9.508328 9.508328 ZT20-23 9.1008515 9.1008515 9.1008515