Year	Tonnes
1917	25.669
1918	25.669
1919	25.669
1920	25.669
1921	25.669
1922	25.669
1923	36.67
1924	44.004
1925	69.673
1926	91.675
1927	234.688
1928	473.043
1929	601.388
1930	678.395
1931	766.403
1932	711.398
1933	726.066
1934	733.4
1935	784.738
1936	876.413
1937	975.422
1938	1030.427
1939	1070.764
1940	1089.099
1941	729.733
1942	1052.429
1943	1056.096
1944	1327.454
1945	1228.445
1946	1103.767
1947	1158.772
1948	1287.117
1949	1301.785
1950	740.734
1951	704.064
1952	894.748
1953	821.408
1954	964.421
1955	1199.109
1956	1298.118
1957	1133.103
1958	1323.787
1959	1294.451
1960	1763.827
1961	1646.483
1962	1565.809
1963	1796.83
1964	2145.195
1965	2277.207
1966	2420.22
1967	2592.569
1968	3116.95
1969	3593.66
1970	4283.056
1971	4224.384
1972	4594.751
1973	5262.145
1974	6090.887
1975	7363.336
1976	8111.404
1977	7484.347
1978	10425.281
1979	12167.106
1980	13443.222
1981	16692.184
1982	19288.42
1983	19556.111
1984	21257.599
1985	19431.433
1986	15276.722
1987	15115.374
1988	17271.57
1989	20267.509
1990	16827.863
1991	16497.833
1992	22280.692
1993	24205.867
1994	13652.241
1995	22841.743
1996	24191.199
1997	18360.669
1998	22460.375
1999	21495.954
2000	20718.55
2001	23116.768
2002	24950.268
2003	26967.118
2004	29046.307
2005	30263.751
2006	28859.29
2007	31888.232
2008	33868.412
2009	36068.612
2010	36460.981
2011	38609.843
2012	38140.467
2013	40997.06
2014	43919.659