1966

6.4

1999

7.1

1987

6.8

2005

5.4

1979

7.8

2005

7.1

2004

7.5

1975

7.8

2001

7.8

1980

7.3

1997

6.6

1999

6.3

2002

6.0

1982

4.4

1970

7.5

1993

6.6

1992

6.7

1993

6.5

1961

0.0

2002

4.4