2001

4.8

1998

7.1

2005

6.2

2005

6.5

2003

5.8

1993

6.5

2006

4.3

1988

4.5

2005

5.9

1990

5.8

2004

6.6

2005

6.4

2008

6.2

1976

0.0

1989

6.3

1977

5.0

2007

6.1

2003

5.5

1987

5.9

1964

7.4