1910    23.780
1911    18.900
1912    34.260
1913    24.140
1914    33.260
1915    37.260
1916    24.020
1917    19.120
1918    10.940
1919    24.280
1920    25.000
1921    30.820
1922    12.880
1923    26.720
1924    21.920
1925    15.540
1926     9.280
1927    16.580
1928    19.960
1929    15.880
1930     9.740
1931    19.820
1932    10.760
1933     9.540
1934    25.060
1935    13.540
1936    21.300
1937    13.440
1938     8.720
1939    15.920
1940    22.140
1941    34.540
1942    18.080
1943    12.400
1944    23.780
1945    13.980
1946     7.420
1947    17.980
1948    12.020
1949     7.540
1950    18.900
1951    19.520
1952     6.020
1953    10.280
1954    17.440
1955    17.800
1956    18.040
1957    15.260
1958    12.520
1959    16.600
1960    18.380
1961    13.920
1962    11.600
1963    16.220
1964    10.880
1965    28.900
1966     9.440
1967    19.100
1968    14.320
1969     3.640
1970     7.340
1971     7.420
1972     8.360
1973    16.100
1974    11.500
1975    15.560
1976    11.400
1977    12.680
1978    16.540
1979    25.740
1980    23.000
1981    14.120
1982    12.300
1983    24.860
1984    32.700
1985    15.760
1986    16.540
1987    14.240
1988    25.740
1989     9.960
1990    12.220
1991    14.940
1992    28.400
1993    25.680
1994    38.220
1995    15.020
1996    28.560
1997    14.400
1998    15.420
1999    19.500
2000    32.200
2001    16.080
2002    52.320
2003    37.980
2004     9.640
2005    16.040
2006    38.840
2007    45.700
2008    25.940
2009     7.280
2010    15.460
2011    34.400
2012    49.300