condition mean min max ZT0-3 14.707959 14.707959 14.707959 ZT4-7 13.4623835 13.4623835 13.4623835 ZT8-11 13.379456999999999 13.379456999999999 13.379456999999999 ZT12-15 13.266368 13.266368 13.266368 ZT16-19 14.880241999999999 14.880241999999999 14.880241999999999 ZT20-23 18.098008 18.098008 18.098008