2001

6.8

2022

8.6

1997

6.1

2004

6.6

2007

6.4

2004

6.5

2003

6.1

2006

6.3

2013

6.1

2016

5.2

2013

7.5

2010

4.8

1988

5.9

1999

5.8

2014

6.5

2009

4.9

1967

7.3

2011

6.8

2015

5.3

2017

6.3