1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
|
2.17
2.93
3.70
4.08
3.82
5.01
4.92
3.96
3.94
4.04
4.15
4.72
5.50
5.78
6.12
7.96
8.17
6.85
6.25
7.63
8.63
8.37
7.61
7.48
9.08
10.93
13.47
|
1.85
2.32
2.74
3.08
2.41
3.96
3.61
3.47
3.56
3.58
4.02
4.10
4.83
4.51
5.48
6.25
5.95
5.00
5.59
6.34
6.82
7.11
6.10
6.58
7.77
8.85
9.21
|
|
|
|
|
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
|
15.93
14.65
11.63
13.48
11.52
8.68
9.08
9.09
9.51
8.77
7.94
6.95
5.83
7.78
7.76
6.69
6.76
5.63
6.19
6.69
4.93
4.74
3.37
3.93
4.45
5.07
5.03
|
12.77
10.22
10.02
11.07
8.73
6.67
6.64
7.71
7.75
7.73
6.19
5.38
4.71
5.09
5.51
5.36
5.77
4.18
4.60
5.17
3.91
2.94
2.27
2.79
3.71
4.35
3.49
|
|
|
|
|
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
|
3.49
2.71
2.58
2.26
1.02
1.60
1.77
1.70
1.96
2.18
|
1.52
1.60
1.18
0.89
0.62
0.71
1.52
1.35
1.07
1.77
|
|
|
|
|
|
