1984

7.2

2008

7.2

1977

7.2

1992

6.8

2006

9.3

2007

7.9

1995

7.9

1972

7.7

1997

7.1

1973

7.0

1995

7.3

1993

6.9

2008

7.5

2012

7.4

1975

6.7

1982

6.3

1995

6.6

2002

8.2

1999

7.7

1958

7.5