1991

7.5

1993

5.5

1954

8.4

2005

6.3

1989

6.8

2008

6.6

1989

6.8

2007

6.1

2009

5.7

2007

6.0

2008

6.0

2017

5.6

2004

5.8

2008

6.2

2000

6.9

1976

7.6

1984

6.8

1967

7.3

1995

6.6

1973

6.7