1967

6.5

1965

6.7

2001

6.0

1998

6.0

2009

5.6

2000

6.2

2007

7.6

2015

6.6

2008

6.8

2013

5.5

1956

7.1

2009

7.5

2000

7.4

2012

6.3

2016

5.8

1989

5.7

1969

7.0

2013

6.5

1989

7.1

1980

6.7