1963

7.7

1985

6.6

2007

7.5

2005

5.8

1998

6.5

1991

6.2

1981

0.0

2001

3.5

2007

4.0

1996

0.0

1988

6.8

2007

4.0

1969

6.5

2007

8.1

1975

6.3

1995

7.8

2007

0.0

1972

3.8

2000

5.0

2006

4.2