1939

7.5

1997

7.6

1998

6.8

1999

6.8

1962

7.3

1953

7.9

2004

7.3

1992

7.7

1999

7.4

2001

7.5

1998

6.6

2000

8.1

2004

7.2

1945

7.7

2001

7.4

1994

7.0

1993

6.7

1988

7.2

2002

7.6