1910    19.660
1911    31.840
1912    32.220
1913    21.340
1914    20.680
1915    21.600
1916    27.160
1917    35.940
1918    14.040
1919    11.560
1920    21.860
1921    25.600
1922    21.840
1923    13.140
1924    25.760
1925    21.980
1926    23.560
1927    17.760
1928    10.500
1929    27.480
1930     8.340
1931    25.760
1932    13.060
1933    21.080
1934    39.940
1935    13.820
1936    20.900
1937    24.640
1938    17.580
1939     9.680
1940    31.160
1941    23.700
1942    16.100
1943    13.120
1944    13.840
1945    12.660
1946    15.340
1947    14.200
1948    12.800
1949    22.980
1950    23.660
1951    16.400
1952    14.080
1953    20.020
1954    22.220
1955    21.060
1956    13.420
1957    17.520
1958    24.780
1959     9.460
1960    17.440
1961    15.040
1962     6.680
1963    12.080
1964    20.760
1965    12.640
1966    16.040
1967    10.660
1968    12.600
1969    11.240
1970    10.120
1971    13.180
1972    15.900
1973    25.280
1974    16.220
1975    19.440
1976    10.980
1977    14.500
1978    29.160
1979    33.880
1980    13.920
1981    21.040
1982    16.520
1983    28.460
1984    18.720
1985    14.420
1986    26.680
1987    26.060
1988    19.480
1989    13.600
1990    25.160
1991    24.940
1992    28.440
1993    22.640
1994    15.640
1995    16.040
1996    25.920
1997    19.140
1998    31.900
1999    19.960
2000    32.900
2001    13.860
2002    21.720
2003    19.720
2004    18.640
2005    18.460
2006    36.120
2007    24.780
2008    20.340
2009    16.760
2010    20.780
2011    30.480
2012    44.340