1931   3200  234   12.4   77.1    ?    778.7     ?  
1932   3084  234   12.9   92.9    ?    745.7     ?  
1933   2864  235   13.9   98.3    ?    768.3     ?  
1934   2803  237   13.6   88.1    ?    733.6     ?  
1935   2755  238   13.2   79.4  20.4   765.7  247.1  
1936   2696  240   13.2   91.0  22.1   816.5  254.9  
1937   2646  241   12.2  100.4  22.4   821.8  272.4  
1938   2701  242   12.6  108.9  21.8   956.8  285.8  
1939   2654  244   12.3  123.6  21.1  1035.7  292.2  
1940   2766  245   12.0  157.3  21.4   951.6  256.0  
1941   2832  246   11.7  154.3  25.3   850.9  205.8  
1942   2964  268   11.2  143.9  27.1   769.7  188.0  
1943   3041  333   11.5  147.5  29.0   811.2  205.8  
1944   3010  335   11.1   97.3  24.2   865.4  207.9  
1945   3018  331   12.5   76.6  24.7   866.8  197.8  
1946   3374  253   15.0   72.8  20.5   968.0  195.9  
1947   3545  243   17.6   68.9  20.7   894.0  198.9  
1948   3441  241   21.2   66.7  22.8   830.8  198.6  
1949   3456  242   22.7   55.0  18.5   811.2  216.1  
1950   3455  237   21.4   55.0  19.3   775.4  212.0  
1951   3503  242   20.7   55.0  20.0   739.8  208.0  
1952   3641  240   19.5   54.7  19.4   740.3  199.3  
1953   3721  233   36.6   47.9  16.1   725.1  176.4  
1954   3828  232   18.1   49.0  16.5   739.9  166.8  
1955   3831  236   17.7   44.4  15.2   663.8  179.7  
1956   3858  245   18.7   40.2  15.3   633.7  198.8  
1957   3925  256   20.8   43.8  17.1   716.5  262.5  
1958   3880  261   22.7   49.5  21.2   761.0  263.4  
1959   3935  265   24.6   50.4  22.3   665.3  253.6  
1960   3895  278   28.5   59.6  28.5   742.6  280.9  
1961   3840  291   31.3   72.4  34.4   789.8  290.9  
1962   3756  290   38.0   70.6  36.0   776.8  274.7  
1963   3669  290   42.0   82.0  43.8   842.2  296.9  
1964   3502  307   48.5   89.5  49.7   799.1  281.3  
1965   3145  313   59.2  101.3  58.6   763.0  264.2  
1966   2812  325   69.7  116.7  71.4   804.6  286.6  
1967   2586  339   80.4  115.2  70.6   781.1  272.0  
1968   2441  338   90.4  122.9  73.0   849.7  274.7