2006

6.1

2005

8.8

2000

6.2

1993

8.0

1979

6.9

1989

5.8

2001

8.0

1986

4.0

1999

7.7

2010

10.0

1999

7.1

6.7

1993

7.7

2004

8.2

1988

7.8

2002

7.5

1984

7.4

2005

7.4

2006

7.1

1966

6.4