1992

6.3

1982

6.1

2009

7.1

1975

6.8

2007

7.3

2002

6.5

1984

5.7

1981

6.7

2017

8.5

2007

4.5

2008

5.0

1977

6.8

1976

5.6

1996

6.8

1972

6.9

2004

5.9

1943

7.5

2004

6.7

1998

7.2

2009

7.3