2011

6.6

2007

6.1

1973

6.5

1991

6.9

1963

7.1

1964

7.4

1967

6.6

1969

6.6

1962

7.0

1974

6.4

1977

6.8

1981

6.5

1985

6.2

1987

6.5

1997

6.4

1975

7.8

1971

6.4

2004

8.0

1996

6.6

1944

6.6