Year	Kilotonnes
1850	0.1754
1851	0.1903
1852	0.2089
1853	0.2213
1854	0.2385
1855	0.2462
1856	0.2572
1857	0.2527
1858	0.2567
1859	0.2783
1860	0.3083
1861	0.3248
1862	0.3287
1863	0.3429
1864	0.3681
1865	0.3893
1866	0.4034
1867	0.4212
1868	0.4283
1869	0.4519
1870	0.4543
1871	0.4731
1872	0.522
1873	0.5503
1874	0.5333
1875	0.5595
1876	0.5718
1877	0.5838
1878	0.5885
1879	0.6024
1880	0.6667
1881	0.6667
1882	0.6667
1883	0.6667
1884	0.6667
1885	0.6667
1886	0.8
1887	0.9333
1888	1.067
1889	1.2
1890	1.333
1891	1.333
1892	1.333
1893	1.333
1894	1.333
1895	1.333
1896	1.467
1897	1.6
1898	1.733
1899	1.867
1900	2
1901	2.133
1902	2.267
1903	2.4
1904	2.533
1905	2.667
1906	2.8
1907	2.933
1908	3.067
1909	3.2
1910	3.333
1911	3.333
1912	3.333
1913	3.333
1914	3.333
1915	3.333
1916	2.933
1917	2.533
1918	2.133
1919	1.733
1920	1.333
1921	2
1922	2.667
1923	3.333
1924	4
1925	4.667
1926	4.667
1927	4.667
1928	4.667
1929	4.667
1930	4.667
1931	4.4
1932	4.133
1933	3.867
1934	3.6
1935	3.333
1936	3.333
1937	3.333
1938	3.333
1939	3.333
1940	3.333
1941	3.2
1942	3.067
1943	2.933
1944	2.8
1945	2.667
1946	2.933
1947	3.2
1948	3.467
1949	3.733
1950	4
1951	5.916
1952	6.421
1953	4.586
1954	4.791
1955	5.333
1956	7.829
1957	7.793
1958	6.534
1959	6.6
1960	7.333
1961	9.144
1962	13.08
1963	21.14
1964	20.74
1965	23.33
1966	16.42
1967	14.64
1968	14.23
1969	17.56
1970	28
1971	37.45
1972	34.97
1973	26.08
1974	39.12
1975	26
1976	27
1977	20.46
1978	16.66
1979	11.81
1980	12
1981	10.08
1982	9.496
1983	5.297
1984	6.018
1985	6.509
1986	6.052
1987	6.618
1988	5.683
1989	7.195
1990	7.35
1991	7.5
1992	7.1
1993	7.5
1994	6.4
1995	4.5
1996	4
1997	3
1998	2
1999	2
2000	1.5