load 'pres_8';

pres1 = pres_8;

for   i1 = 1:size(sst1,1);
    k1=1;
    for j1 = 1:12:size(pres1,2);
        a(i1,k1)=mean(pres1(i1,j1:j1+11));
        k1=k1+1;
    end
end

a (a == -999) = NaN;
save -ascii pres_8_anual a
load 'pres_8_anual'