s&p 500 monthly monthly returns for 1955
s&p 500 monthly monthly returns for 1956
s&p 500 monthly monthly returns for 1957
s&p 500 monthly monthly returns for 1958
s&p 500 monthly monthly returns for 1959
s&p 500 monthly monthly returns for 1960
s&p 500 monthly monthly returns for 1961
s&p 500 monthly monthly returns for 1962
s&p 500 monthly monthly returns for 1963
s&p 500 monthly monthly returns for 19643
s&p 500 monthly monthly returns for 1964
s&p 500 monthly monthly returns for 1965
s&p 500 monthly monthly returns for 1966
s&p 500 monthly monthly returns for 1967
s&p 500 monthly monthly returns for 1968
