1997

7.3

2013

6.9

2011

7.1

2018

8.1

2001

7.8

1997

7.0

2002

7.3

2009

7.2

2016

7.1

2006

6.2

2009

8.0

2004

7.5

2005

8.2

1989

8.3

2003

5.2

2010

7.7

2014

8.2

2007

8.2

2022

8.1

2019

7.5