1910    23.117
1911    24.350
1912    31.267
1913    18.267
1914    16.900
1915    26.217
1916    34.400
1917    29.217
1918    11.450
1919    21.183
1920    17.400
1921    26.967
1922    15.817
1923    17.050
1924    27.950
1925    13.267
1926    24.050
1927    16.833
1928    15.250
1929    24.700
1930    11.583
1931    24.450
1932    18.533
1933    29.533
1934    35.583
1935    16.117
1936    18.933
1937    12.767
1938    18.017
1939    17.283
1940    22.217
1941    31.133
1942    13.000
1943    10.683
1944    15.383
1945    15.083
1946    13.533
1947    16.583
1948    19.450
1949    19.300
1950    28.833
1951    20.083
1952    11.967
1953    22.883
1954    31.433
1955    22.133
1956    16.983
1957    17.767
1958    19.167
1959    15.700
1960    19.167
1961    15.833
1962     6.833
1963    14.733
1964    25.483
1965    18.383
1966    16.117
1967    10.783
1968    14.150
1969    15.933
1970    10.500
1971    12.300
1972    13.733
1973    17.383
1974    10.917
1975    16.417
1976    20.267
1977     8.900
1978    17.100
1979    27.067
1980    10.767
1981    18.333
1982    16.583
1983    26.167
1984    14.517
1985    28.967
1986    17.683
1987    18.833
1988    16.083
1989    21.800
1990    20.633
1991    19.650
1992    24.983
1993    22.433
1994    13.633
1995    20.700
1996    31.083
1997    17.383
1998    42.533
1999    28.983
2000    14.967
2001    20.133
2002    23.317
2003    25.267
2004    29.983
2005    35.667
2006    29.367
2007    28.150
2008    26.167
2009    14.533
2010    20.500
2011    26.550
2012    42.433