1978

6.8

2008

6.1

1960

5.6

2012

5.7

1981

7.0

1984

7.1

1968

7.3

1964

5.6

1959

5.4

2009

6.5

1992

4.7

1991

6.5

1981

6.0

2008

6.5

1943

6.5

1938

6.5

1892

4.7

1983

7.6

2002

6.9

1964

5.7