1895    52.63
1896    51.83
1897    54.88
1898    52.34
1899    55.32
1900    55.22
1901    54.13
1902    54.31
1903    52.91
1904    54.71
1905    53.99
1906    53.78
1907    53.63
1908    53.89
1909    54.72
1910    54.85
1911    52.68
1912    53.44
1913    54.21
1914    55.16
1915    55.09
1916    52.73
1917    53.47
1918    53.53
1919    53.19
1920    53.86
1921    55.45
1922    55.38
1923    53.71
1924    54.09
1925    52.67
1926    53.85
1927    55.77
1928    53.99
1929    52.58
1930    53.59
1931    56.76
1932    53.32
1933    55.89
1934    55.87
1935    53.38
1936    53.91
1937    54.19
1938    55.10
1939    55.54
1940    54.27
1941    55.05
1942    54.58
1943    53.72
1944    54.81
1945    54.46
1946    53.97
1947    55.30
1948    54.44
1949    55.13
1950    54.62
1951    52.81
1952    53.70
1953    56.16
1954    55.83
1955    53.77
1956    54.62
1957    52.82
1958    55.17
1959    52.96
1960    55.35
1961    53.35
1962    55.21
1963    57.26
1964    53.97
1965    54.46
1966    54.21
1967    53.86
1968    53.90
1969    53.44
1970    53.43
1971    54.40
1972    52.60
1973    55.10
1974    53.51
1975    54.04
1976    51.56
1977    54.86
1978    54.56
1979    54.43
1980    54.37
1981    54.61
1982    53.46
1983    55.20
1984    53.45
1985    52.81
1986    53.68
1987    54.58
1988    54.46
1989    54.31
1990    56.01
1991    53.58
1992    53.63
1993    52.38
1994    54.74
1995    54.26
1996    52.82
1997    54.31
1998    56.88
1999    56.02
2000    53.55