2001

6.0

2012

6.2

2004

5.7

2009

5.7

2014

6.5

2015

6.4

1984

6.5

1989

5.8

2013

6.1

2006

5.5

5.3

2010

6.8

2018

7.1

2011

6.0

2017

5.9

1997

6.1

2015

6.3

2021

5.7

1975

4.5