2014

5.3

2017

6.2

1997

5.6

2016

6.3

1970

6.9

2017

7.1

2006

6.6

1989

6.5

2007

7.3

2008

6.6

2002

7.4

1972

7.0

1996

6.6

2003

5.3

2003

7.2

2006

6.4

1977

6.7

1995

6.5

1997

6.0

1989

5.9