2009

6.6

1996

7.7

1981

7.9

1984

7.3

1992

6.6

1998

7.2

1973

5.7

2000

6.2

1993

7.9

2004

8.3

1992

7.6

2000

7.0

1997

8.1

1995

6.5

2004

8.6

1998

7.4

1960

7.5

2006

1.0

2005

7.1

2002

6.9