Year	Tonnes
1950	25.669
1951	25.669
1952	29.336
1953	29.336
1954	40.337
1955	44.004
1956	36.67
1957	25.669
1958	66.006
1959	73.34
1960	58.672
1961	73.34
1962	69.673
1963	80.674
1964	99.009
1965	102.676
1966	99.009
1967	102.676
1968	128.345
1969	135.679
1970	168.682
1971	216.353
1972	253.023
1973	326.363
1974	370.367
1975	605.055
1976	729.733
1977	865.412
1978	949.753
1979	1045.095
1980	1195.442
1981	1360.457
1982	1958.178
1983	2489.893
1984	2948.268
1985	3157.287
1986	3153.62
1987	3355.305
1988	3406.643
1989	3498.318
1990	3766.009