1999

5.4

1997

6.8

2005

6.7

2005

7.3

1999

6.2

2004

7.0

2007

6.9

1992

7.4

1944

7.6

1991

5.9

2005

7.2

2006

7.1

2002

6.3

2006

7.6

1990

6.7

2002

6.7

1995

6.7

1982

4.5

2001

6.1

1969

6.0