1920   27.6                            
1921   43.9                            
1922   41.4                            
1923   40.0                            
1924   59.2                            
1925   65.2                            
1926   92.4                            
1927   90.8                            
1928   98.1                            
1929   124.8                           
1930   174.1                           
1931   124.6                           
1932   149.1                           
1933   146.8                           
1934   166.0                           
1935   155.6                           
1936   159.9                           
1937   166.2                           
1938   218.3                           
1939   193.3                           
1940   218.9                           
1941   249.8                           
1942   323.4                           
1943   297.7                           
1944   395.7                           
1945   380.5