1910    19.320
1911    27.020
1912    35.000
1913    20.540
1914    21.160
1915    26.000
1916    23.920
1917    33.180
1918    14.780
1919    15.640
1920    24.260
1921    25.020
1922    17.360
1923    15.240
1924    28.680
1925    21.660
1926    21.400
1927    18.040
1928    10.880
1929    23.800
1930    11.600
1931    26.380
1932    13.880
1933    17.600
1934    43.180
1935    13.600
1936    18.220
1937    19.760
1938    17.540
1939    11.640
1940    30.440
1941    24.020
1942    15.080
1943    15.720
1944    15.760
1945    10.600
1946    11.680
1947     8.960
1948    15.280
1949    23.920
1950    23.000
1951    19.340
1952    13.600
1953    16.580
1954    26.460
1955    21.700
1956    14.320
1957    14.760
1958    24.160
1959     9.600
1960    17.540
1961    18.760
1962     7.840
1963    13.020
1964    18.980
1965    15.120
1966    15.100
1967     8.980
1968    13.020
1969     9.600
1970    11.300
1971    16.500
1972    13.480
1973    24.460
1974    13.780
1975    21.360
1976    11.920
1977    11.860
1978    26.560
1979    33.460
1980    11.340
1981    19.300
1982    18.640
1983    26.360
1984    19.360
1985    13.080
1986    21.380
1987    21.940
1988    22.100
1989    13.900
1990    21.640
1991    24.400
1992    23.380
1993    27.060
1994    18.240
1995    16.520
1996    25.120
1997    17.360
1998    32.080
1999    23.360
2000    31.740
2001    14.720
2002    24.400
2003    25.920
2004    17.660
2005    21.140
2006    37.700
2007    33.560
2008    20.440
2009    17.660
2010    24.000
2011    37.660
2012    47.420