1984

7.1

1989

6.5

1970

6.3

2016

4.9

2012

4.8

2006

6.2

1980

6.7

2011

5.9

2016

5.9

1985

6.5

1990

5.5

1988

7.6

2011

6.1

1982

6.9

2008

6.8

2010

5.5

1998

6.0

2005

4.3

2001

7.0

2015

5.7