condition mean min max ZT0-3 19.7746 19.7746 19.7746 ZT4-7 17.5193 17.5193 17.5193 ZT8-11 18.56095 18.56095 18.56095 ZT12-15 18.7815 18.7815 18.7815 ZT16-19 22.7209 22.7209 22.7209 ZT20-23 20.8507 20.8507 20.8507