2004

6.7

2008

6.7

1999

7.4

1988

7.0

2004

7.3

2005

6.3

1997

8.4

2006

7.0

1991

7.5

1966

7.7

1998

7.3

2010

4.3

2013

5.7

2003

6.3

2006

6.1

1985

7.5

1981

5.0

2005

4.8

1997

6.3

2008

7.2