condition mean min max ZT0-3 3.2414990435 2.908386565 3.574611522 ZT4-7 1.9951485942500002 1.7757880485000002 2.21450914 ZT8-11 2.1194807424999995 1.7722091769999997 2.466752308 ZT12-15 2.79836605825 2.3705659265 3.22616619 ZT16-19 2.46903549475 2.119349795 2.8187211945 ZT20-23 4.746257214250001 4.061583409 5.430931019500001