Year	Tonnes
1950	267.691
1951	322.696
1952	388.702
1953	418.038
1954	469.376
1955	462.042
1956	528.048
1957	597.721
1958	597.721
1959	605.055
1960	619.723
1961	583.053
1962	649.059
1963	1125.769
1964	1232.112
1965	1041.428
1966	1305.452
1967	1158.772
1968	1261.448
1969	1191.775
1970	1430.13
1971	1510.804
1972	1679.486
1973	1969.179
1974	1972.846
1975	2108.525
1976	2211.201
1977	2288.208
1978	2390.884
1979	2390.884
1980	2134.194
1981	1833.5
1982	1767.494
1983	1903.173
1984	1606.146
1985	1987.514
1986	1991.181
1987	2449.556
1988	2471.558
1989	2588.902
1990	2511.895
1991	3171.955
1992	3318.635
1993	3795.345
1994	4594.751
1995	5027.457
1996	4569.082
1997	5474.831
1998	5812.195
1999	5698.518
2000	5742.522
2001	5947.874
2002	6039.549
2003	6552.929
2004	6365.912
2005	6453.92
2006	6846.289
2007	6978.301
2008	6545.595
2009	6442.919
2010	6457.587
2011	6648.271
2012	6662.939
2013	6230.233
2014	6285.238