condition mean min max ZT0-3 3.5230574999999997 3.2958749999999997 3.75024 ZT4-7 2.88918 2.88918 2.88918 ZT8-11 3.738585 3.738585 3.738585 ZT12-15 0 0 0 ZT16-19 3.53979 3.53979 3.53979 ZT20-23 5.052715 5.052715 5.052715