Year	Kilotonnes
1850	0.00331
1851	0.00221
1852	0.00415
1853	0.00374
1854	0.00463
1855	0.00448
1856	0.00617
1857	0.00706
1858	0.00743
1859	0.00702
1860	0.01001
1861	0.00986
1862	0.01102
1863	0.00981
1864	0.01254
1865	0.01238
1866	0.01039
1867	0.01312
1868	0.0127
1869	0.01543
1870	0.0137
1871	0.01249
1872	0.01522
1873	0.01351
1874	0.0152
1875	0.01533
1876	0.01649
1877	0.0145
1878	0.01566
1879	0.01525
1880	0.01379
1881	0.01395
1882	0.01535
1883	0.01143
1884	0.01517
1885	0.01402
1886	0.01308
1887	0.01111
1888	0.01356
1889	0.01085
1890	0.01186
1891	0.01106
1892	0.0126
1893	0.01401
1894	0.01459
1895	0.01476
1896	0.01496
1897	0.01505
1898	0.01818
1899	0.01987
1900	0.02166
1901	0.02834
1902	0.02917
1903	0.03325
1904	0.03492
1905	0.03898
1906	0.03879
1907	0.04207
1908	0.04634
1909	0.0504
1910	0.05152
1911	0.06106
1912	0.06077
1913	0.05462
1914	0.0541
1915	0.0668
1916	0.08086
1917	0.0975
1918	0.1085
1919	0.09112
1920	0.09813
1921	0.08131
1922	0.09631
1923	0.1235
1924	0.1229
1925	0.1334
1926	0.1448
1927	0.1591
1928	0.1905
1929	0.2043
1930	0.1781
1931	0.1598
1932	0.1098
1933	0.1324
1934	0.171
1935	0.179
1936	0.1827
1937	0.2482
1938	0.2441
1939	0.2408
1940	0.2512
1941	0.2862
1942	0.2663
1943	0.2939
1944	0.3073
1945	0.3234
1946	0.3659
1947	0.3418
1948	0.3549
1949	0.367
1950	0.4682
1951	0.5189
1952	0.5059
1953	0.4984
1954	0.5069
1955	0.5436
1956	0.5636
1957	0.5743
1958	0.5564
1959	0.5701
1960	0.5771
1961	0.5611
1962	0.5554
1963	0.5649
1964	0.5804
1965	0.5994
1966	0.6096
1967	3.728
1968	9.816
1969	9.661
1970	9.25
1971	13.38
1972	14.04
1973	12.91
1974	12.63
1975	8.82
1976	7.493
1977	11.39
1978	14.24
1979	12.09
1980	17.11
1981	15.1
1982	12.62
1983	8.259
1984	9.35
1985	9.473
1986	14.44
1987	14.98
1988	15.03
1989	15.39
1990	9.548
1991	8.387
1992	10.87
1993	9.332
1994	9.864
1995	12.75
1996	11.64
1997	11.02
1998	1.998
1999	1.418
2000	1.792