1995

6.4

1997

6.5

1992

7.4

1994

6.3

1991

6.3

2003

7.4

2006

5.9

1956

0.0

2007

6.1

1953

7.7

1976

5.5

1984

5.7

1932

6.1

1993

4.9

2009

5.0

1996

5.5

1990

6.1

1986

4.7

1919

4.7

1999

4.3