1939

7.5

1999

6.8

1987

7.3

1998

6.6

2004

7.2

1995

8.0

1982

4.8

1967

7.4

1972

6.2

2006

5.3

2001

6.1

1997

6.1

1976

3.3

1994

5.7

1993

5.0

2002

7.0

1947

6.5

1979

7.8

2001

7.8

1978

7.4