1991

8.3

2003

6.5

1946

7.7

2006

5.4

1997

6.6

1998

7.1

1997

6.8

2001

6.0

2005

6.0

1994

7.0

1999

6.1

1983

6.2

1998

6.2

1997

5.7

1995

6.2

1984

6.4

1985

7.1

2002

6.2

1998

7.2

2000

6.3