condition mean min max ZT0-3 2.935375 2.935375 2.935375 ZT4-7 0.7534935 0.7534935 0.7534935 ZT8-11 2.5177449999999997 2.5177449999999997 2.5177449999999997 ZT12-15 2.27627 2.27627 2.27627 ZT16-19 3.7486949999999997 3.7486949999999997 3.7486949999999997 ZT20-23 4.9214649999999995 4.9214649999999995 4.9214649999999995