1962

7.0

1963

7.1

1967

6.6

1969

6.6

1974

6.4

1981

6.5

1985

6.2

1987

6.5

1997

6.4

2005

7.4

2006

6.3

2007

6.5

1966

7.3

1929

6.5

1995

5.4

1971

6.8

2001

6.2

1954

8.0

2002

7.2

1971

8.2