condition mean min max ZT0-3 5.381943333333333 3.42284 6.71694 ZT4-7 3.22673 3.22673 3.22673 ZT8-11 3.15558 3.15558 3.15558 ZT12-15 4.544595 4.1349800000000005 4.95421 ZT16-19 5.198865 5.198865 5.198865 ZT20-23 6.7132950000000005 6.7132950000000005 6.7132950000000005