1993

7.0

1986

8.0

1989

6.3

1959

6.9

1940

7.1

1985

6.4

1967

6.4

2003

5.7

1989

5.0

1982

7.1

2006

6.1

2008

7.8

2010

6.4

2001

7.7

2004

7.3

1992

7.6

2007

6.2

1984

2.0

1991

0.0

1996

5.8