1973

7.4

1999

6.8

1997

7.8

1997

6.8

1993

5.0

2004

7.2

1990

6.6

2002

5.3

2001

7.5

1995

7.9

2002

10.0

1960

7.2

2003

0.0

2001

7.8

1999

7.0

2008

6.6

2007

7.3

1992

5.7

2004

6.9

1984

6.7