1939

7.5

1986

7.6

2006

5.6

1995

8.4

1998

6.6

1931

8.1

2000

8.1

2004

7.2

1951

7.7

1958

7.4

1993

5.5

2005

6.9

2002

7.6

1990

2.5

1962

3.8

1972

7.7

1944

8.1

2001

7.8

1994

7.0

1966

7.3