1984

7.7

2003

7.2

1997

8.4

2009

4.0

1982

7.4

1976

7.4

1988

7.8

2004

7.8

1982

6.4

2006

7.2

2002

8.1

1993

7.1

2005

0.0

2001

6.6

1999

8.4

2004

8.2

2007

5.8

1996

5.9

1991

1.0

2000

0.0