1981

4.0

2004

8.1

2005

4.5

1985

6.3

2000

7.0

1974

6.3

1986

7.0

2006

7.6

2001

6.5

2006

7.1

1993

7.4

2001

7.8

1966

6.4

2000

8.0

2002

7.1

2003

8.7

2006

7.8

1999

0.0

2003

8.0

1992

7.1