1992

3.3

2008

4.1

1994

6.2

1996

5.9

2016

6.7

1977

6.8

2006

4.0

2010

5.5

2002

4.4

2009

0.0

2014

4.8

1998

6.0

2001

6.7

2005

6.3

1997

6.0

2017

4.5

2008

5.3

1999

6.3

1998

5.5

2009

5.8