function [y z] = annual_avg_1d(x,year,month)

nt=length(year);

day = [31 28 31 30 31 30 31 31 30 31 30 31];


y = zeros(max(year)-min(year)+1,1);

z = [min(year):1:max(year)];

days = zeros(max(year)-min(year)+1,1);

for n=1:nt
  
  days(year(n)-min(year)+1,1) = days(year(n)-min(year)+1,1)+day(month(n));

end


for n=1:nt
   y(year(n)-min(year)+1) = squeeze(y(year(n)-min(year)+1))+x(n)*day(month(n))/days(year(n)-min(year)+1,1);
end