1971

7.2

1987

7.1

1975

7.5

2014

7.6

2014

5.3

1945

5.7

1962

7.0

1963

7.1

1964

7.4

1967

6.6

1969

6.6

2001

7.9

2002

7.7

2004

8.0

2005

7.8

2007

7.7

1974

6.4

1977

6.8

1981

6.5

1985

6.2