Year	Thousands Of Long Tons
1915	8550.00
1916	8992.00
1917	9717.00
1918	9539.00
1919	7894.00
1920	9067.00
1921	3703.00
1922	5881.00
1923	8482.00
1924	8201.00
1925	7385.00
1926	3596.00
1927	9097.00
1928	8520.00
1929	9636.00
1930	7326.00
1931	5203.00
1932	5261.00
1933	7024.00
1934	8850.00
1935	9859.00
1936	11785.0
1937	12984.0
1938	10394.0