1889
|
30.8
|
1890
|
36.0
|
1891
|
30.7
|
1892
|
31.8
|
1893
|
31.9
|
1894
|
30.5
|
1895
|
28.4
|
1896
|
34.8
|
1897
|
32.8
|
1898
|
31.1
|
1899
|
23.8
|
1900
|
31.7
|
1901
|
32.2
|
1902
|
32.6
|
1903
|
30.0
|
1904
|
34.0
|
1905
|
29.0
|
1906
|
32.6
|
1907
|
38.3
|
1908
|
34.3
|
1909
|
34.1
|
1910
|
27.6
|
1911
|
34.2
|
1912
|
26.5
|
1913
|
28.2
|
1914
|
30.9
|
1915
|
30.2
|
1916
|
31.9
|
1917
|
31.8
|
1918
|
31.8
|
1919
|
30.6
|
1920 |
33.6 |
1921 |
35.8 |
1922 |
31.2 |
1923 |
35.0 |
1924 |
33.0 |
1925 |
30.3 |
1926 |
35.0 |
1927 |
34.6 |
1928 |
31.3 |
1929 |
28.7 |
1930 |
32.4 |
|
|
1931
|
33.7
|
1932
|
34.4
|
1933
|
30.0
|
1934
|
39.6
|
1935
|
37.5
|
1936
|
31.3
|
1937
|
31.0
|
1938
|
34.5
|
1939
|
32.2
|
1940
|
31.6
|
1941
|
34.2
|
1942
|
29.7
|
1943
|
36.1
|
1944
|
31.4
|
1945
|
32.2
|
1946
|
31.9
|
1947
|
32.3
|
1948
|
29.2
|
1949
|
28.6
|
1950
|
35.3
|
1951 |
32.6 |
1952 |
34.8 |
1953 |
35.4 |
1954 |
37.6 |
1955 |
31.0 |
1956 |
31.2 |
1957 |
35.0 |
1958 |
36.5 |
1959 |
32.3 |
1960 |
27.9 |
1961 |
32.0 |
1962 |
28.3 |
1963 |
31.3 |
1964 |
29.2 |
1965 |
33.8 |
1966 |
31.1 |
1967 |
33.4 |
1968 |
28.9 |
1969 |
35.0 |
1970 |
36.8 |
1971 |
35.9 |
1972 |
34.0 |
|
|
1973
|
29.2
|
1974
|
31.7
|
1975
|
31.3
|
1976
|
35.9
|
1977
|
32.7
|
1978
|
30.0
|
1979
|
24.8
|
1980
|
33.1
|
1981
|
39.4
|
1982 |
33.1 |
1983 |
34.3 |
1984 |
27.8 |
1985 |
30.1 |
1986 |
35.2 |
1987 |
32.4 |
1988 |
27.4 |
1989 |
29.2 |
1990 |
31.0 |
1991 |
30.7 |
1992 |
34.8 |
1993 |
28.4 |
1994 |
31.3 |
1995 |
34.0 |
1996 |
31.5 |
1997 |
31.0 |
1998 |
31.8 |
1999 |
35.3 |
2000 |
35.9 |
2001 |
28.5 |
2002 |
30.6 |
2003 |
33.0 |
2004 |
33.0 |
2005 |
34.5 |
2006 |
32.9 |
2007 |
29.5 |
2008 |
30.0 |
2009 |
34.1 |
2010 |
27.9 |
2011 |
29.8 |
2012 |
31.3 |
2013 |
30.3 |
2014 |
31.2 |
|
|
2015 |
33.0 |
2016 |
35.9 |
2017
|
34.7 |
2018
|
33.7 |
2019 |
33.2 |
2020 |
33.8 |
2021 |
30.8 |
2022 |
33.8 |
|