2005

6.5

1998

6.8

1987

6.5

1980

7.0

1983

6.2

2004

7.2

2008

6.1

1990

5.5

1943

5.5

1985

6.5

1986

6.2

1975

6.1

1996

6.1

2003

3.0

1974

6.1

2004

6.4

1992

6.9

1986

6.6

1992

5.3

2002

5.8