Year Kilotonnes
1850 0.00114
1851 0.00114
1852 0.00229
1853 0.00343
1854 0.00458
1855 0.00573
1856 0.00687
1857 0.00802
1858 0.00917
1859 0.01032
1860 0.01147
1861 0.0228
1862 0.03414
1863 0.04547
1864 0.05681
1865 0.06814
1866 0.07948
1867 0.09082
1868 0.1022
1869 0.1135
1870 0.1248
1871 0.1362
1872 0.148
1873 0.1598
1874 0.1716
1875 0.1834
1876 0.1952
1877 0.207
1878 0.2189
1879 0.2307
1880 0.2425
1881 0.2746
1882 0.256
1883 0.2577
1884 0.2593
1885 0.2854
1886 0.3114
1887 0.3374
1888 0.3646
1889 0.4053
1890 0.4284
1891 0.3609
1892 0.4657
1893 0.4068
1894 0.5057
1895 0.4464
1896 0.5021
1897 0.5657
1898 0.585
1899 0.5901
1900 0.705
1901 0.7679
1902 0.4048
1903 0.4432
1904 0.5263
1905 0.5717
1906 0.5589
1907 0.6053
1908 0.7936
1909 0.7274
1910 0.8679
1911 0.7542
1912 0.8641
1913 0.9875
1914 1.067
1915 1.221
1916 1.342
1917 1.153
1918 1.238
1919 1.354
1920 1.421
1921 1.949
1922 2.009
1923 2.462
1924 2.598
1925 2.574
1926 2.528
1927 2.764
1928 2.868
1929 3.226
1930 3.512
1931 2.895
1932 2.414
1933 2.913
1934 3.515
1935 3.767
1936 3.907
1937 4.978
1938 4.784
1939 5.096
1940 4.738
1941 4.885
1942 4.98
1943 4.996
1944 4.853
1945 4.812
1946 4.662
1947 4.927
1948 5.733
1949 5.935
1950 6.203
1951 2.975
1952 4.584
1953 0.9453
1954 1.747
1955 1.091
1956 0.4733
1957 0.4857
1958 1.248
1959 1.407
1960 1.933
1961 0.5304
1962 0.5354
1963 1.673
1964 1.425
1965 1.628
1966 8.962
1967 17.91
1968 23.87
1969 25.32
1970 29.71
1971 26.55
1972 25.99
1973 24.94
1974 26.33
1975 24.15
1976 21.53
1977 23.07
1978 20.58
1979 23.84
1980 24.78
1981 20.95
1982 19.11
1983 17.66
1984 18.28
1985 17.6
1986 17.61
1987 17.7
1988 18.46
1989 19.06
1990 18.27
1991 17.51
1992 17.55
1993 18.21
1994 18.69
1995 19.42
1996 19.94
1997 20.84
1998 22.12
1999 23.64
2000 25.89