Year	Tonnes
1950	498.712
1951	447.374
1952	539.049
1953	528.048
1954	539.049
1955	557.384
1956	660.06
1957	762.736
1958	803.073
1959	689.396
1960	828.742
1961	704.064
1962	766.403
1963	803.073
1964	1034.094
1965	1162.439
1966	1371.458
1967	1760.16
1968	1653.817
1969	1796.83
1970	1767.494
1971	2464.224
1972	2167.197
1973	3186.623
1974	2306.543
1975	2284.541
1976	2790.587
1977	2013.183
1978	2203.867
1979	2071.855
1980	1884.838
1981	2123.193
1982	2167.197
1983	2218.535
1984	2368.882
1985	2357.881
1986	2299.209
1987	2390.884
1988	2288.208
1989	2207.534
1990	2266.206
1991	2398.218
1992	2324.878
1993	2596.236
1994	2405.552
1995	3553.323
1996	3461.648
1997	2882.262
1998	2555.899
1999	2537.564
2000	2651.241
2001	3127.951
2002	3589.993
2003	3806.346
2004	4363.73
2005	5504.167
2006	6028.548
2007	5896.536
2008	6142.225
2009	5918.538
2010	7106.646
2011	8093.069
2012	9545.201
2013	11177.016
2014	11562.051