1976

5.7

1955

7.2

1992

6.4

2008

0.0

2005

6.9

1986

6.0

1971

6.5

1989

7.4

2007

6.1

2008

4.5

2000

6.7

2007

7.3

2003

5.5

2001

5.0

2001

5.7

1957

7.0

2002

5.5

2002

7.2