Year	Tonnes
1970	3.667
1971	3.667
1972	3.667
1973	3.667
1974	3.667
1975	3.667
1976	3.667
1977	7.334
1978	11.001
1979	22.002
1980	22.002
1981	25.669
1982	33.003
1983	29.336
1984	51.338
1985	62.339
1986	55.005
1987	102.676
1988	110.01
1989	62.339
1990	128.345
1991	187.017
1992	216.353
1993	183.35
1994	212.686
1995	249.356
1996	300.694
1997	392.369
1998	381.368
1999	385.035
2000	396.036
2001	385.035
2002	418.038
2003	377.701
2004	308.028
2005	396.036
2006	392.369
2007	392.369
2008	421.705
2009	388.702
2010	487.711
2011	733.4
2012	817.741
2013	920.417
2014	1001.091