2016

6.1

1981

6.5

2013

8.0

2008

6.8

2004

6.8

1991

6.9

2008

8.1

1989

6.6

2011

6.7

1995

6.8

2015

7.2

2005

5.4

2001

7.5

2001

7.9

1992

5.7

2001

6.8

2001

7.4

2012

7.4

2012

5.8

1986

6.6