1989

7.0

1990

6.6

2002

6.0

2010

5.6

1998

6.6

2007

6.3

2004

7.3

1940

7.1

1991

8.3

1999

6.3

1967

5.3

1963

7.9

1983

6.1

2008

8.1

1990

6.1

2009

6.8

1999

6.3

2003

6.2

1990

7.3

1984

7.7