| 1833 20.65 |
| 1834 20.65 |
| 1835 20.65 |
| 1836 20.65 |
| 1837 20.65 |
| 1838 20.65 |
| 1839 20.65 |
| 1840 20.65 |
| 1841 20.65 |
| 1842 20.65 |
| 1843 20.65 |
| 1844 20.65 |
| 1845 20.65 |
| 1846 20.65 |
| 1847 20.65 |
| 1848 20.65 |
| 1849 20.65 |
| 1850 20.65 |
| 1851 20.65 |
| 1852 20.65 |
| 1853 20.65 |
| 1854 20.65 |
| 1855 20.65 |
| 1856 20.65 |
| 1857 20.65 |
| 1858 20.65 |
| 1859 20.65 |
| 1860 20.65 |
| 1861 20.65 |
| 1862 20.65 |
|
| 1863 20.65 |
| 1864 20.65 |
| 1865 20.65 |
| 1866 20.65 |
| 1867 20.65 |
| 1868 20.65 |
| 1869 20.65 |
| 1870 20.65 |
| 1871 20.65 |
| 1872 20.66 |
| 1873 20.66 |
| 1874 20.66 |
| 1875 20.66 |
| 1876 20.66 |
| 1877 20.66 |
| 1878 20.66 |
| 1879 20.65 |
| 1880 20.66 |
| 1881 20.66 |
| 1882 20.66 |
| 1883 20.66 |
| 1884 20.66 |
| 1885 20.66 |
| 1886 20.65 |
| 1887 20.65 |
| 1888 20.66 |
| 1889 20.65 |
| 1890 20.66 |
| 1891 20.68 |
| 1892 20.68 |
|
| 1893 20.68 |
| 1894 20.66 |
| 1895 20.65 |
| 1896 20.71 |
| 1897 20.71 |
| 1898 20.71 |
| 1899 20.66 |
| 1900 20.68 |
| 1901 20.71 |
| 1902 20.69 |
| 1903 20.67 |
| 1904 20.68 |
| 1905 20.64 |
| 1906 20.62 |
| 1907 20.66 |
| 1908 20.67 |
| 1909 20.68 |
| 1910 20.64 |
| 1911 20.64 |
| 1912 20.65 |
| 1913 20.64 |
| 1914 20.72 |
| 1915 20.72 |
| 1916 20.72 |
| 1917 20.72 |
| 1918 20.72 |
| 1919 20.70 |
| 1920 20.68 |
| 1921 20.58 |
| 1922 20.66 |
|
| 1923 21.32 |
| 1924 20.69 |
| 1925 20.64 |
| 1926 20.63 |
| 1927 20.64 |
| 1928 20.66 |
| 1929 20.63 |
| 1930 20.65 |
| 1931 17.06 |
| 1932 20.69 |
| 1933 26.33 |
| 1934 34.69 |
| 1935 34.84 |
| 1936 34.87 |
| 1937 34.79 |
| 1938 34.85 |
| 1939 34.42 |
| 1940 33.85 |
| 1941 33.85 |
| 1942 33.85 |
| 1943 33.85 |
| 1944 33.85 |
| 1945 34.71 |
| 1946 34.71 |
| 1947 34.71 |
| 1948 34.71 |
| 1949 31.69 |
| 1950 34.72 |
| 1951 34.72 |
| 1952 34.60 |
|
| 1953 34.84 |
| 1954 35.04 |
| 1955 35.03 |
| 1956 34.99 |
| 1957 34.95 |
| 1958 35.10 |
| 1959 35.10 |
| 1960 35.27 |
| 1961 35.25 |
| 1962 35.23 |
| 1963 35.09 |
| 1964 35.10 |
| 1965 35.12 |
| 1966 35.13 |
| 1967 34.95 |
| 1968 38.69 |
| 1969 41.09 |
| 1970 35.94 |
| 1971 40.80 |
| 1972 58.16 |
| 1973 97.32 |
| 1974 159.26 |
| 1975 161.02 |
| 1976 124.84 |
| 1977 147.71 |
| 1978 193.22 |
| 1979 306.68 |
| 1980 612.56 |
| 1981 460.03 |
| 1982 375.67 |
|
| 1983 424.35 |
| 1984 360.48 |
| 1985 317.26 |
| 1986 367.66 |
| 1987 446.46 |
| 1988 436.94 |
| 1989 381.44 |
| 1990 383.51 |
| 1991 362.11 |
| 1992 343.82 |
| 1993 359.77 |
| 1994 384.00 |
| 1995 384.17 |
| 1996 387.77 |
| 1997 330.98 |
|