Year	Tonnes
1969	11.001
1970	11.001
1971	11.001
1972	11.001
1973	11.001
1974	11.001
1975	14.668
1976	14.668
1977	29.336
1978	29.336
1979	25.669
1980	29.336
1981	66.006
1982	51.338
1983	51.338
1984	22.002
1985	22.002
1986	22.002
1987	22.002
1988	22.002
1989	22.002
1990	36.67
1991	36.67
1992	36.67
1993	40.337
1994	40.337
1995	40.337
1996	47.671
1997	47.671
1998	47.671
1999	47.671
2000	47.671
2001	33.003
2002	29.336
2003	33.003
2004	55.005
2005	62.339
2006	66.006
2007	66.006
2008	69.673
2009	69.673
2010	69.673
2011	69.673
2012	69.673
2013	69.673
2014	69.673