condition mean min max ZT0-3 25.96555 25.96555 25.96555 ZT4-7 20.51695 20.51695 20.51695 ZT8-11 25.6283 25.6283 25.6283 ZT12-15 21.95555 21.95555 21.95555 ZT16-19 27.2056 27.2056 27.2056 ZT20-23 25.82725 25.82725 25.82725