condition mean min max ZT0-3 0.5199078333333333 0.2316595 1.043855 ZT4-7 1.057005 1.057005 1.057005 ZT8-11 1.218795 1.218795 1.218795 ZT12-15 1.0925455 0.9122709999999999 1.27282 ZT16-19 1.4275600000000002 1.4275600000000002 1.4275600000000002 ZT20-23 0.7660425 0.7660425 0.7660425