Year	Tonnes
1970	3667
1971	7334
1972	11001
1973	14668
1974	18335
1975	22002
1976	25669
1977	29336
1978	33003
1979	36670
1980	40337
1981	44004
1982	47671
1983	51338
1984	55005
1985	58672
1986	62339
1987	66006
1988	69673
1989	73340
1990	80674
1991	88008
1992	95342
1993	102676
1994	110010
1995	117344
1996	124678
1997	132012
1998	139346
1999	146680
2000	154014
2001	161348
2002	168682
2003	172349
2004	176016
2005	179683
2006	183350
2007	187017
2008	194351
2009	198018
2010	201685
2011	209019
2012	216353
2013	223687
2014	234688