1992

6.3

2002

6.7

1982

6.1

1994

6.8

2005

5.1

1994

7.8

2009

6.0

2009

4.7

2017

8.5

2007

4.5

2008

5.0

2006

4.9

1976

5.6

1996

6.8

1972

6.9

2004

5.9

1948

6.7

1943

7.5

2006

6.5

2004

6.4