1991

5.8

2018

5.8

2004

7.3

1997

6.0

2018

6.9

1988

5.7

2003

6.4

2000

5.1

2008

6.1

2011

7.8

2005

5.2

2014

7.4

2013

7.6

2002

5.8

2019

6.5

2009

5.3

1999

6.1

2009

6.7

2015

8.4

2011

6.5