This was a tricky one. I was able to get something in, but there are extra rows at the end that aren't importable.
This file appears to have been generated as a human readable file, so it's not surprising a machine has some trouble.
opts = delimitedTextImportOptions('Delimiter',{'\t',' '},'NumVariables',17);
opts = setvartype(opts,2:16,'double');
opts.ConsecutiveDelimitersRule = 'join';
opts.DataLines = [3, inf]; % could also be [3 38] if you don't want the trailing rows
opts.VariableNamesLine = 2;
T = readtable('ANN_month.txt',opts,'ReadVariableNames',true);
head(T)
If you need a matrix:
A = T{:,2:16};
