1985

6.9

2010

6.7

2010

4.9

1998

5.3

2008

5.7

2009

5.9

1997

6.3

1996

7.0

1962

7.5

1971

7.4

2002

5.1

2007

4.9

2007

5.6

2000

1.7

1993

6.6

2006

6.5

2008

0.0

1996

6.6

1998

4.4

2005

6.3