2011

8.3

2004

8.3

2020

6.9

1998

7.2

1997

7.3

2007

7.4

2001

6.6

2009

8.0

2002

7.5

1996

5.4

2006

7.9

1992

5.8

1984

7.3

1972

7.7

2015

8.1

1993

6.7

1990

8.1

2008

7.7

1976

8.0

1994

6.8