Year	Tonnes
1950	33.003
1951	14.668
1952	29.336
1953	40.337
1954	4418.735
1955	2442.222
1956	2295.542
1957	2933.6
1958	1818.832
1959	2530.23
1960	3575.325
1961	2592.569
1962	3817.347
1963	2838.258
1964	3534.988
1965	3828.348
1966	3366.306
1967	2951.935
1968	11518.047
1969	4543.413
1970	2343.213
1971	1756.493
1972	1243.113
1973	2405.552
1974	1877.504
1975	1565.809
1976	1837.167
1977	2115.859
1978	2156.196
1979	2178.198
1980	2123.193
1981	2871.261
1982	3989.696
1983	3839.349
1984	4224.384
1985	5500.5
1986	5115.465
1987	5328.151
1988	6197.23
1989	6497.924
1990	5830.53