1969

6.9

1966

7.5

1973

7.3

1972

7.1

1965

7.7

1967

7.1

2002

6.2

1983

6.4

2002

6.5

1981

6.8

1974

6.6

1977

6.7

1953

6.8

1980

6.4

1991

7.2

2011

7.1

1985

6.8

1986

6.6

1979

6.3

1992

6.0