Year	Tonnes
1957	1730.824
1958	2299.209
1959	1800.497
1960	1393.46
1961	2093.857
1962	2577.901
1963	3399.309
1964	3703.67
1965	2530.23
1966	674.728
1967	3058.278
1968	5419.826
1969	7205.655
1970	18210.322
1971	16593.175
1972	22240.355
1973	21220.929
1974	21968.997
1975	24543.231
1976	30036.397
1977	28309.24
1978	33164.348
1979	36123.617
1980	31433.524
1981	26849.774
1982	29750.371
1983	34997.848
1984	33402.703
1985	33417.371
1986	35027.184
1987	32599.63
1988	36105.282
1989	41888.141
1990	44495.378
1991	45269.115
1992	48426.402
1993	51187.653
1994	61682.607
1995	42174.167
1996	49698.851
1997	58429.978
1998	48617.086
1999	50069.218
2000	49005.788
2001	49541.17
2002	47230.96
2003	31132.83
2004	28474.255
2005	30359.093
2006	30799.133
2007	19926.478
2008	36134.618
2009	55932.751
2010	55643.058
2011	45221.444
2012	36372.973
2013	55676.061
2014	56372.791