Year	Kilotonnes
1850	0.01909
1851	0.02071
1852	0.04139
1853	0.06192
1854	0.08232
1855	0.1029
1856	0.1245
1857	0.1459
1858	0.1659
1859	0.1869
1860	0.2071
1861	0.2278
1862	0.2485
1863	0.2683
1864	0.2878
1865	0.3074
1866	0.327
1867	0.3478
1868	0.2975
1869	0.3888
1870	0.4092
1871	0.4927
1872	0.4119
1873	0.4367
1874	0.4172
1875	0.4359
1876	0.4579
1877	0.4793
1878	0.4981
1879	0.5183
1880	0.5395
1881	0.5564
1882	0.5742
1883	0.5898
1884	0.6061
1885	0.6216
1886	0.6352
1887	0.6503
1888	0.6648
1889	0.6794
1890	0.6925
1891	0.706
1892	0.72
1893	0.6828
1894	0.6938
1895	0.6849
1896	0.7771
1897	0.8062
1898	0.9407
1899	0.7956
1900	1.027
1901	0.9753
1902	0.8484
1903	0.8602
1904	0.7801
1905	0.6849
1906	0.7569
1907	0.9984
1908	1.397
1909	1.381
1910	1.712
1911	1.883
1912	2.088
1913	2.297
1914	2.174
1915	2.071
1916	2.054
1917	2.012
1918	1.942
1919	1.782
1920	1.712
1921	1.935
1922	2.095
1923	2.638
1924	3.45
1925	4.452
1926	4.435
1927	5.603
1928	5.867
1929	6.879
1930	7.877
1931	7.305
1932	7.452
1933	7.247
1934	7.466
1935	6.849
1936	4.925
1937	3.335
1938	1.765
1939	1.106
1940	0.6849
1941	0.5876
1942	0.5656
1943	0.5008
1944	0.4096
1945	0.3425
1946	0.7969
1947	1.852
1948	4.12
1949	10.58
1950	16.44
1951	18.56
1952	16.81
1953	17.72
1954	19.32
1955	20.89
1956	18.87
1957	20.04
1958	20.47
1959	32.79
1960	37.33
1961	37.6
1962	40.58
1963	48.29
1964	51.3
1965	67.47
1966	67.74
1967	74.96
1968	76.67
1969	85.09
1970	96.58
1971	121
1972	128.8
1973	173.3
1974	157.9
1975	179.5
1976	204.4
1977	197.9
1978	191.9
1979	216.2
1980	200
1981	230.7
1982	218.1
1983	234.8
1984	241.1
1985	250
1986	251.4
1987	269.4
1988	267.6
1989	266.4
1990	245.5
1991	266.5
1992	272
1993	271.5
1994	256
1995	267.5
1996	261
1997	257.5
1998	262
1999	268.5
2000	245