2007

6.9

2003

6.2

1986

6.1

2002

6.3

1988

6.3

2000

5.8

1992

7.4

2001

7.3

1970

7.1

1964

7.1

1996

6.4

2004

5.6

2005

6.4

2004

3.0

2008

6.8

2007

4.8

1980

6.6

2007

3.0

2003

5.3

1992

5.0