condition mean min max ZT0-3 3.0031883333333336 1.415395 4.3468800000000005 ZT4-7 4.95177 4.95177 4.95177 ZT8-11 15.8144 15.8144 15.8144 ZT12-15 22.597524999999997 22.0913 23.103749999999998 ZT16-19 14.89275 14.89275 14.89275 ZT20-23 7.313485 7.313485 7.313485