Year	Millions Of Dollars
1918	29289.0
1919	34851.0
1920	34312.0
1921	26535.0
1922	28863.0
1923	31849.0
1924	31497.0
1925	32868.0
1926	32159.0
1927	31846.0
1928	32339.0
1929	33369.0
1930	27851.0
1931	22434.0
1932	17844.0
1933	19582.0
1934	20259.0
1935	21826.0
1936	24091.0
1937	26313.0