1919 0.264000 1920 0.276000 1921 0.292000 1922 0.312000 1923 0.334000 1924 0.362000 1925 0.392000 1926 0.428000 1927 0.466000 1928 0.501000 1929 0.524000 1930 0.555000 1931 0.591000 1932 0.616000 1933 0.638000 1934 0.666000 1935 0.696000 1936 0.730000 1937 0.760000 1938 0.780000 1939 0.820000 1940 0.850000 1941 0.880000 1942 0.920000 1943 0.950000 1944 0.970000 1945 0.980000 1946 1.02000