Year	Ratio
1900	1721
1901	1540
1902	1627
1903	1454
1904	1391
1905	1484
1906	1686
1907	1496
1908	1534
1909	1378
1910	903.8
1911	2327
1912	2331
1913	2029
1914	2494
1915	2330
1916	2298
1917	2045
1918	2187
1919	2270
1920	1767
1921	2100
1922	2029
1923	2156
1924	1910
1925	1850
1926	1910
1927	1750
1928	1918
1929	2036
1930	2136
1931	2080
1932	1916
1933	1857
1934	2012
1935	2680
1936	2165
1937	1992
1938	2013
1939	1824
1940	1607
1941	1532
1942	1445
1943	1335
1944	1365
1945	1694
1946	1552
1947	1056
1948	826.2
1949	654.6
1950	555.4
1951	577.1
1952	579.8
1953	485
1954	456.7
1955	405.2
1956	376.5
1957	370.8
1958	385.5
1959	338.7
1960	302.5
1961	260.9
1962	295.9
1963	245.2
1964	278.5
1965	239.3
1966	221.9
1967	170.5
1968	179.3
1969	153.2
1970	144.9
1971	138.3
1972	130.1
1973	118.9
1974	108.6
1975	99.4
1976	98
1977	91.9
1978	86.1
1979	86.1
1980	91.9
1990	49
1995	71
2000	55
2005	41
2010	32
2013	29