1969

3.6

2006

7.4

1968

7.6

1975

5.5

1988

7.1

1976

5.6

2007

3.8

2003

7.8

2001

5.1

1988

3.6

1999

5.5

2007

5.9

1977

5.6

1960

6.1

1993

7.7

2002

5.5

2009

7.5

2009

6.5

2000

3.7

1995

0.0