1998

7.3

2010

4.6

2017

3.3

2005

5.9

2002

6.2

1978

6.0

2003

5.8

2008

4.5

2006

5.5

2008

4.4

2009

3.8

2009

6.6

2008

5.8

1984

4.8

2006

7.6

2006

6.3

2007

6.6

2008

5.0

2020

6.7

1992

7.0