condition mean min max ZT0-3 3.471875 2.06976 5.039255 ZT4-7 1.5588229999999998 1.5588229999999998 1.5588229999999998 ZT8-11 1.78083 1.78083 1.78083 ZT12-15 2.26936175 2.0723935 2.46633 ZT16-19 2.10132 2.10132 2.10132 ZT20-23 3.3603199999999998 3.3603199999999998 3.3603199999999998