Year Kilotonnes 1850 0.0005 1851 0.0005 1852 0.00101 1853 0.00151 1854 0.00201 1855 0.00252 1856 0.00302 1857 0.00353 1858 0.00404 1859 0.00454 1860 0.00505 1861 0.01003 1862 0.01502 1863 0.02001 1864 0.02499 1865 0.02998 1866 0.03497 1867 0.03996 1868 0.04495 1869 0.04994 1870 0.05493 1871 0.05992 1872 0.1199 1873 0.1799 1874 0.2399 1875 0.3 1876 0.3602 1877 0.4203 1878 0.4806 1879 0.5408 1880 0.6011 1881 0.6615 1882 0.7219 1883 0.7823 1884 0.8428 1885 0.9034 1886 0.9639 1887 1.025 1888 1.085 1889 1.146 1890 1.207 1891 1.267 1892 1.328 1893 1.389 1894 1.45 1895 1.511 1896 1.572 1897 1.633 1898 1.694 1899 1.755 1900 1.817 1901 1.878 1902 1.939 1903 2 1904 2.062 1905 2.123 1906 2.185 1907 2.246 1908 2.308 1909 2.369 1910 2.431 1911 8.685 1912 28.15 1913 49.02 1914 51.82 1915 64.02 1916 75.18 1917 40.04 1918 62 1919 78.05 1920 84.7 1921 115.1 1922 127 1923 127.4 1924 122.2 1925 123.3 1926 117.1 1927 126.2 1928 84.31 1929 92.69 1930 93.16 1931 108.5 1932 125.2 1933 136.4 1934 123 1935 132.3 1936 156.3 1937 182.7 1938 204 1939 252.7 1940 195.7 1941 228 1942 217.4 1943 224.4 1944 203.6 1945 213.5 1946 200.9 1947 210.1 1948 258 1949 228.8 1950 229.4 1951 171.6 1952 218.1 1953 259 1954 220.8 1955 238.7 1956 253.3 1957 262.5 1958 303.3 1959 244.8 1960 195.2 1961 200.8 1962 216 1963 193.8 1964 236.5 1965 260.4 1966 267.6 1967 141.1 1968 4.935 1969 8.944 1970 88.69 1971 153.3 1972 160.9 1973 176.8 1974 187.3 1975 187.3 1976 186.6 1977 193.8 1978 210.5 1979 275.1 1980 330.6 1981 344.8 1982 334.7 1983 306.6 1984 298.7 1985 302.3 1986 281.2 1987 308.8 1988 333.7 1989 335.5 1990 340.9 1991 375 1992 386.1 1993 294.2 1994 332.6 1995 382.2 1996 407.3 1997 414.1 1998 333.2 1999 348.7 2000 292.6