1962

7.0

1963

7.1

1965

6.7

1971

6.4

1975

7.2

1977

6.8

1987

6.5

1997

6.4

2005

6.5

1956

7.5

1974

7.5

1953

7.7

1985

6.3

2005

6.7

1997

6.6

1999

6.3

2002

6.0

1984

6.2

1998

6.9

1966

5.0