2008

4.3

2003

6.2

1998

6.0

2004

6.8

1979

6.1

1997

5.5

1985

6.0

2004

4.2

1985

5.3

1977

6.5

1986

5.8

1987

5.8

1999

3.9

1996

4.1

1992

5.5

1979

4.3

2001

6.5

1981

5.5

1996

5.2

1971

5.0