1966

7.6

1992

4.0

2005

7.5

1998

8.3

1982

6.7

2004

7.3

1987

6.5

1985

7.8

2011

0.0

1990

6.9

2001

5.9

1991

7.4

2004

6.5

1992

7.5

2006

6.8

2004

7.6

2007

7.2

1993

5.7

1997

6.8

1997

6.7