1967

7.6

1990

9.0

1998

7.0

2005

7.3

1989

7.4

2011

8.1

1976

0.0

1995

3.0

1991

6.9

2004

6.0

1975

6.9

1987

7.0

1999

7.3

2006

0.0

1996

6.4

2001

6.6

2009

0.0

1983

6.0

1969

8.2

1987

7.5