condition mean min max ZT0-3 3.4808166666666667 3.082705 4.21379 ZT4-7 1.7728000000000002 1.7728000000000002 1.7728000000000002 ZT8-11 4.420885 4.420885 4.420885 ZT12-15 17.525275 16.431449999999998 18.6191 ZT16-19 13.6302 13.6302 13.6302 ZT20-23 10.623285 10.623285 10.623285