1939

7.5

1962

7.3

2000

8.1

2004

7.2

2005

6.9

2005

6.7

1947

6.5

1950

8.3

1978

7.4

1997

7.5

1989

7.4

1995

6.6

1942

6.6

1942

7.3

1975

7.5

1994

7.0

1958

7.6

1999

7.2

2006

6.1

1999

7.7