1990

7.9

2009

7.4

2004

6.2

2016

8.6

2001

8.0

1997

8.4

2005

7.0

1997

8.3

2006

7.7

2010

8.1

2011

8.5

1994

6.8

2006

8.2

1998

7.9

2016

7.1

2013

7.1

1996

6.8

2008

7.6

1993

7.9

2010

8.2