Year	Tonnes
1950	47.671
1951	44.004
1952	55.005
1953	58.672
1954	102.676
1955	58.672
1956	47.671
1957	84.341
1958	161.348
1959	143.013
1960	165.015
1961	161.348
1962	253.023
1963	355.699
1964	484.044
1965	557.384
1966	612.389
1967	612.389
1968	883.747
1969	1272.449
1970	1452.132
1971	1525.472
1972	1507.137
1973	1481.468
1974	1723.49
1975	1485.135
1976	1477.801
1977	1474.134
1978	1507.137
1979	1947.177
1980	2042.519
1981	1939.843
1982	601.388
1983	711.398
1984	700.397
1985	722.399
1986	729.733
1987	766.403
1988	817.741
1989	667.394
1990	473.043
1991	278.692
1992	282.359
1993	315.362
1994	311.695
1995	326.363
1996	337.364
1997	348.365
1998	374.034
1999	392.369
2000	421.705
2001	491.378
2002	487.711
2003	520.714
2004	616.056
2005	726.066
2006	748.068
2007	667.394
2008	564.718
2009	517.047
2010	792.072
2011	891.081
2012	1026.76
2013	957.087
2014	935.085