Year Tonnes
1860 267.691
1861 880.08
1862 1496.136
1863 2112.192
1864 2728.248
1865 3344.304
1866 3960.36
1867 4572.749
1868 5188.805
1869 5804.861
1870 6420.917
1871 7036.973
1872 7649.362
1873 8265.418
1874 8881.474
1875 9497.53
1876 16417.159
1877 17249.568
1878 18081.977
1879 19431.433
1880 20586.538
1881 21741.643
1882 22233.021
1883 23747.492
1884 24528.563
1885 25753.341
1886 27073.461
1887 28437.585
1888 30480.104
1889 32269.6
1890 34510.137
1891 35778.919
1892 36321.635
1893 37128.375
1894 38059.793
1895 39500.924
1896 40472.679
1897 42834.227
1898 43791.314
1899 44928.084
1900 44601.721
1901 46603.903
1902 47227.293
1903 48114.707
1904 48584.083
1905 50014.213
1906 52229.081
1907 54891.323
1908 55903.415
1909 55562.384
1910 54982.998
1911 55679.728
1912 59244.052
1913 61968.633
1914 56493.802
1915 56369.124
1916 59995.787
1917 56416.795
1918 48100.039
1919 45441.464
1920 45067.43
1921 43281.601
1922 38628.178
1923 40828.378
1924 50113.222
1925 47161.287
1926 47817.68
1927 51315.998
1928 54029.578
1929 60439.494
1930 53281.51
1931 49852.865
1932 43450.283
1933 39739.279
1934 39695.275
1935 40865.048
1936 44400.036
1937 53780.222
1938 61623.935
1939 67703.821
1940 76306.603
1941 76805.315
1942 82837.53
1943 91458.647
1944 87201.26
1945 46277.54
1946 57597.569
1947 65364.275
1948 70644.755
1949 74264.084
1950 76460.617
1951 81477.073
1952 87116.919
1953 90292.541
1954 96427.432
1955 100094.432
1956 107406.43
1957 112180.864
1958 122573.142
1959 122686.819
1960 130849.561
1961 142019.243
1962 151344.424
1963 159202.805
1964 165686.061
1965 161443.342
1966 160533.926
1967 160200.229
1968 167607.569
1969 177933.841
1970 204002.544
1971 214031.789
1972 216030.304
1973 216947.054
1974 219499.286
1975 229700.88
1976 238681.363
1977 245865.016
1978 248149.557
1979 241728.64
1980 244610.902
1981 241999.998
1982 239671.453
1983 240052.821
1984 248182.56
1985 244838.256
1986 246569.08
1987 244640.238
1988 240756.885
1989 232858.167
1990 217757.461
1991 200819.588