condition mean min max ZT0-3 2.8343225 2.632385 3.03626 ZT4-7 3.522865 3.522865 3.522865 ZT8-11 3.17844 3.17844 3.17844 ZT12-15 0 0 0 ZT16-19 3.82308 3.82308 3.82308 ZT20-23 4.167339999999999 4.167339999999999 4.167339999999999