1976

7.5

1996

6.7

2006

7.0

2011

7.1

1964

7.0

2012

4.5

1966

6.3

2012

6.0

1982

6.2

2009

5.6

2000

5.1

1998

6.0

1980

6.7

2016

5.9

2010

6.8

1982

6.9

1981

6.1

1995

6.8

2016

4.2

1999

5.6