1994

7.7

1995

7.7

1967

7.6

1990

9.0

1998

7.0

2005

7.3

1999

6.8

2002

7.4

1989

7.4

2006

8.1

2011

8.1

1999

7.4

2011

9.0

1976

0.0

1995

3.0

1991

6.9

2004

6.0

1975

6.9

1987

7.0

2003

6.9