1974

7.0

2001

7.4

2007

6.7

1983

8.2

2000

7.4

2006

6.0

1999

6.2

1964

6.8

1994

5.7

2002

5.3

1948

8.2

2005

7.2

2003

6.5

1996

6.3

2005

6.3

1982

6.8

1984

6.1

1968

1.0

2012

6.4

1995

7.9