Year	Tonnes
1928	29.336
1929	33.003
1930	40.337
1931	91.675
1932	150.347
1933	176.016
1934	190.684
1935	234.688
1936	212.686
1937	370.367
1938	465.709
1939	319.029
1940	396.036
1941	388.702
1942	330.03
1943	355.699
1944	421.705
1945	524.381
1946	685.729
1947	832.409
1948	942.419
1949	1089.099
1950	2563.233
1951	2929.933
1952	3567.991
1953	4176.713
1954	3589.993
1955	3560.657
1956	3523.987
1957	3058.278
1958	3270.964
1959	3373.64
1960	3641.331
1961	3777.01
1962	3080.28
1963	3960.36
1964	4422.402
1965	4261.054
1966	5467.497
1967	5416.159
1968	5628.845
1969	5826.863
1970	7293.663
1971	8203.079
1972	8049.065
1973	9640.543
1974	11136.679
1975	11111.01
1976	11547.383
1977	12702.488
1978	13076.522
1979	15958.784
1980	15944.116
1981	15856.108
1982	17058.884
1983	17795.951
1984	17814.286
1985	17865.624
1986	18881.383
1987	20117.162
1988	21176.925
1989	22918.75
1990	23542.14
1991	24975.937
1992	26039.367
1993	28217.565
1994	29640.361
1995	30373.761
1996	31195.169
1997	31862.563
1998	32038.579
1999	33153.347
2000	33905.082
2001	37715.095
2002	38254.144
2003	37561.081
2004	43310.937
2005	45771.494
2006	47425.311
2007	50267.236
2008	52900.142
2009	52482.104
2010	55958.42
2011	57685.577
2012	62731.369
2013	59082.704
2014	59863.775