1992

6.4

1978

6.9

2015

4.4

1956

7.1

2009

5.0

2014

6.7

1977

6.3

2010

7.4

2007

7.2

1973

7.5

1994

6.5

1995

4.6

2005

5.2

2006

6.0

1999

5.9

2015

6.1

2005

7.4

2012

6.2

1998

7.5

2000

7.3