1985

6.2

1948

5.0

2005

6.3

1994

3.6

1996

7.6

2005

6.2

1999

4.3

1997

7.0

1971

7.2

2003

5.9

2001

6.1

1989

4.0

2006

7.6

2006

6.5

2007

6.8

1991

6.8

1994

5.1

2001

4.7

1996

6.4

1994

6.1