1980

5.9

2008

6.2

2013

6.1

6.1

2016

6.7

1999

6.7

1989

6.0

1989

9.2

2011

5.7

6.8

2012

5.6

2003

5.8

2008

5.2

2010

6.9

2014

5.8

2008

5.7

2020

9.4

2020

7.0

2014

5.8