1994

6.1

2008

5.5

2008

5.5

2000

6.4

1999

6.8

2007

7.4

2005

7.5

1959

7.0

1974

5.7

1997

5.9

2009

6.9

2009

5.3

2004

5.8

1983

6.7

2013

7.2

1962

4.6

2011

7.4

2014

6.3

2013

7.2

1981

2.5