condition mean min max ZT0-3 22.12865 21.8557 22.401600000000002 ZT4-7 19.1814 19.1814 19.1814 ZT8-11 14.91 14.91 14.91 ZT12-15 0 0 0 ZT16-19 23.9134 23.9134 23.9134 ZT20-23 18.95595 18.95595 18.95595