1976

8.2

2005

7.5

2011

6.5

1995

7.7

2015

7.8

1973

5.9

2010

7.0

1999

7.2

1969

7.5

1995

5.8

2003

6.7

2001

7.5

2018

8.4

2005

7.4

1992

7.8

1957

8.2

1950

8.3

1992

8.1

1996

7.9

2002

6.9