1995

6.4

1987

7.8

1939

5.0

2005

6.6

2004

7.2

1994

6.7

1997

7.5

1981

5.0

2006

6.7

2007

6.6

2002

5.8

1993

6.2

1976

7.2

2005

6.7

1992

7.8

2007

7.6

2007

6.5

1953

5.6

1937

0.0

2017

5.4