1995

1.0

2010

3.9

2004

5.6

1987

7.3

1995

6.6

2002

7.2

1994

7.0

2005

6.7

1999

7.7

2001

6.7

2006

6.2

2003

7.2

1969

2.5

2006

5.4

2004

4.8

2001

6.1

1976

3.0

1996

5.0

1997

1.0

2004

7.2