1976

4.5

2003

6.2

2000

5.7

2008

6.0

2009

7.5

2002

7.1

2005

6.3

2006

7.8

1987

6.1

1996

8.0

2014

3.0

2007

6.1

2017

7.0

2009

3.8

2004

5.6

2007

6.9

2003

4.0

2001

4.3

1986

6.8

2009

5.2