1983

6.8

2008

6.7

1977

5.6

1977

6.0

2009

5.9

1976

5.2

2008

3.2

1951

6.3

1983

6.3

2002

6.4

2017

5.1

1998

3.8

2008

3.2

1985

6.6

2003

5.8

2006

7.1

1974

6.1

2004

6.4

1958

7.7

1971

7.0