condition mean min max ZT0-3 20.007425 19.97905 20.035800000000002 ZT4-7 27.22685 27.22685 27.22685 ZT8-11 26.3114 26.3114 26.3114 ZT12-15 0 0 0 ZT16-19 13.657599999999999 13.657599999999999 13.657599999999999 ZT20-23 15.5927 15.5927 15.5927