1986

8.4

2010

8.5

2003

7.8

2014

7.7

2017

8.0

2005

8.2

1994

6.8

2008

8.1

1962

7.3

2016

8.6

1969

7.8

1991

7.6

2001

8.6

1995

6.4

1990

7.0

1996

7.6

2006

8.6

1995

7.7

2008

8.9

2009

8.0