Year	Tonnes
1947	7.334
1948	22.002
1949	25.669
1950	348.365
1951	359.366
1952	594.054
1953	619.723
1954	627.057
1955	916.75
1956	986.423
1957	1034.094
1958	1067.097
1959	1114.768
1960	1041.428
1961	1030.427
1962	1243.113
1963	1250.447
1964	1749.159
1965	1547.474
1966	1672.152
1967	1569.476
1968	2350.547
1969	2654.908
1970	3109.616
1971	3523.987
1972	4675.425
1973	5966.209
1974	6417.25
1975	6340.243
1976	6332.909
1977	5614.177
1978	5449.162
1979	6809.619
1980	6457.587
1981	6167.894
1982	6340.243
1983	7913.386
1984	7444.01
1985	7293.663
1986	8181.077
1987	9754.22
1988	9834.894
1989	10366.609
1990	9229.839
1991	10043.913
1992	10923.993
1993	11763.736
1994	12475.134
1995	15885.444
1996	17326.575
1997	18001.303
1998	18397.339
1999	18562.354
2000	19790.799
2001	19816.468
2002	21330.939
2003	21514.289
2004	18309.331
2005	18639.361
2006	19783.465
2007	21173.258
2008	20711.216
2009	20227.172
2010	21022.911
2011	21228.263
2012	22123.011
2013	21440.949
2014	21539.958