1896 54.2 1900 49.4 1904 49.2 1908 50.0 1912 48.2 1920 49.6 1924 47.6 1928 47.8 1932 46.2 1936 46.5 1948 46.2 1952 45.9 1956 46.7 1960 44.9 1964 45.1 1968 43.8 1972 44.66 1976 44.26 1980 44.60 1984 44.27 1988 43.87