condition mean min max ZT0-3 17.05835 17.05835 17.05835 ZT4-7 20.34695 20.34695 20.34695 ZT8-11 4.6082 4.6082 4.6082 ZT12-15 14.583675 14.583675 14.583675 ZT16-19 19.32105 19.32105 19.32105 ZT20-23 10.27015 10.27015 10.27015