1971

7.2

1945

5.7

1973

6.5

2006

7.6

2001

6.8

1967

5.7

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

1957

7.0

1979

6.2

1968

5.3