Year	Tonnes
1950	47.671
1951	47.671
1952	47.671
1953	47.671
1954	47.671
1955	66.006
1956	69.673
1957	73.34
1958	84.341
1959	88.008
1960	84.341
1961	88.008
1962	106.343
1963	102.676
1964	135.679
1965	132.012
1966	139.346
1967	227.354
1968	154.014
1969	161.348
1970	216.353
1971	187.017
1972	234.688
1973	264.024
1974	330.03
1975	502.379
1976	480.377
1977	799.406
1978	557.384
1979	487.711
1980	814.074
1981	275.025
1982	718.732
1983	935.085
1984	715.065
1985	858.078
1986	924.084
1987	993.757
1988	1008.425
1989	957.087
1990	733.4
1991	707.731
1992	682.062
1993	641.725
1994	630.724
1995	590.387
1996	568.385
1997	539.049
1998	513.38
1999	491.378
2000	480.377
2001	502.379
2002	586.72
2003	594.054
2004	594.054
2005	594.054
2006	594.054
2007	608.722
2008	601.388
2009	597.721
2010	612.389
2011	605.055
2012	608.722
2013	608.722
2014	608.722