condition mean min max ZT0-3 4.34251 4.34251 4.34251 ZT4-7 4.33892 4.33892 4.33892 ZT8-11 4.2234799999999995 4.2234799999999995 4.2234799999999995 ZT12-15 4.324426666666667 4.324426666666667 4.324426666666667 ZT16-19 4.49967 4.49967 4.49967 ZT20-23 4.4758 4.4758 4.4758