1984

7.4

2005

7.7

2008

6.8

2006

6.8

2003

7.2

2004

7.7

2007

6.6

1982

3.5

1985

5.0

2000

7.5

1994

7.2

2007

7.5

1987

5.0

1992

6.0

2014

7.0

2009

6.6

1991

4.8

1965

5.5

1996

6.6

1999

7.9