1990

5.7

2010

5.3

2011

7.0

2005

8.2

2006

7.1

2002

7.7

2007

7.4

2001

5.1

2012

7.6

2013

5.6

2005

8.2

1990

7.4

1999

7.9

2009

7.9

2008

7.3

1997

8.0

2007

7.6

1997

6.5

2000

0.0

1992

6.4

2013

7.6

2005

7.9

2017

7.9

1956

4.6

2002

7.3

1998

6.7