Year	Tonnes
1958	3667
1959	11001
1960	55005
1961	146680
1962	231021
1963	319029
1964	429039
1965	531715
1966	634391
1967	737067
1968	839743
1969	960754
1970	1103767
1971	1254114
1972	1415462
1973	1584144
1974	1789496
1975	2009516
1976	2218535
1977	2467891
1978	2816256
1979	3223293
1980	3655999
1981	4213383
1982	4789102
1983	5383156
1984	5848865
1985	6325575
1986	6805952
1987	7322999
1988	7876716
1989	8698124
1990	9281177
1991	9908234
1992	10538958
1993	11166015
1994	11811407
1995	12438464
1996	13146195
1997	13952935
1998	14814680
1999	15746098
2000	16787526
2001	17784950
2002	18789708
2003	19867806
2004	20971573
2005	22097342
2006	23457799
2007	25104282
2008	27022123
2009	28954632
2010	30916477
2011	33127678
2012	35756917
2013	38815195
2014	41664454
