Year	Tonnes
1920	3.667
1921	7.334
1922	80.674
1923	161.348
1924	216.353
1925	172.349
1926	238.355
1927	231.021
1928	282.359
1929	304.361
1930	388.702
1931	249.356
1932	51.338
1933	3.667
1934	18.335
1935	33.003
1936	40.337
1937	102.676
1938	121.011
1939	88.008
1940	77.007
1941	102.676
1942	143.013
1943	220.02
1944	172.349
1945	172.349
1946	311.695
1947	326.363
1948	374.034
1949	476.71
1950	1481.468
1951	1749.159
1952	2086.523
1953	2291.875
1954	2819.923
1955	3391.975
1956	3179.289
1957	3333.303
1958	2929.933
1959	2702.579
1960	2321.211
1961	2357.881
1962	2174.531
1963	2295.542
1964	1976.513
1965	2471.558
1966	2405.552
1967	2291.875
1968	3369.973
1969	3652.332
1970	2713.58
1971	2962.936
1972	3021.608
1973	3193.957
1974	3369.973
1975	3237.961
1976	3413.977
1977	3487.317
1978	3538.655
1979	3755.008
1980	3501.985
1981	3777.01
1982	3072.946
1983	4026.366
1984	3964.027
1985	3641.331
1986	3377.307
1987	3854.017
1988	4019.032
1989	4393.066
1990	4070.37
1991	2962.936
1992	2816.256
1993	2592.569
1994	1639.149
1995	2123.193
1996	2317.544
1997	1899.506
1998	1668.485
1999	1382.459
2000	814.074
2001	836.076
2002	927.751
2003	986.423
2004	1199.109
2005	1499.803
2006	1609.813
2007	1756.493
2008	1859.169
2009	1749.159
2010	2020.517
2011	2493.56
2012	2401.885
2013	3589.993
2014	4671.758