1991

8.3

2003

6.5

1946

7.7

2006

5.4

1998

7.1

2005

6.0

1994

7.0

2006

6.5

2008

6.5

1998

6.2

1997

5.7

1995

6.2

1993

6.8

1985

7.1

2002

6.2

1998

7.2

2002

5.6

2000

6.3

1999

5.5

1960

7.6