1973

0.0

1981

0.0

1988

8.1

2006

4.0

1999

6.5

2000

6.5

2007

7.0

2003

0.0

1990

5.6

2002

6.9

2006

7.1

1973

7.7

1974

7.2

1970

3.0

2004

7.9

2001

8.1

1985

7.0

1961

6.7

0.0

1993

6.0