1979

5.6

2008

5.5

2004

5.9

2003

5.7

2004

6.9

2000

7.2

1961

5.6

2014

4.2

1991

7.7

2003

7.2

1998

7.9

1998

6.6

1953

7.2

2005

6.2

1978

6.3

1984

6.1

1986

7.1

2023

6.4

2001

7.0

1959

6.9