1982

5.9

2001

7.0

2011

4.3

2005

7.3

1992

6.7

1999

5.3

1980

7.1

1998

6.6

2003

6.1

1991

6.9

1996

6.2

1942

7.4

2012

6.8

2012

5.2

2000

5.2

2000

6.2

2011

5.2

1953

7.2

2006

5.1

1994

6.6