Year	Tonnes
1905	14.668
1909	157.681
1910	198.018
1911	234.688
1912	293.36
1913	341.031
1914	487.711
1915	608.722
1916	506.046
1918	498.712
1919	590.387
1920	766.403
1921	825.075
1922	843.41
1923	1008.425
1924	1059.763
1925	1690.487
1926	1815.165
1927	1881.171
1928	2167.197
1929	2489.893
1930	2346.88
1931	2486.226
1932	2929.933
1933	3454.314
1934	4594.751
1935	5405.158
1936	6343.91
1937	6787.617
1938	9079.492
1939	11855.411
1940	15243.719
1941	17003.879
1942	18771.373
1943	18191.987
1944	19218.747