1996

6.6

2002

7.1

2001

3.3

1994

7.0

2005

6.8

2006

7.1

1999

7.8

2003

7.2

2001

6.7

2006

6.3

1972

6.9

2005

5.5

2006

5.4

2004

4.8

2001

6.1

1999

3.7

2005

5.5

2007

7.2

2007

6.6

1953

4.2