2006

6.5

1987

6.6

1994

5.9

1989

7.1

2009

6.8

1980

7.3

2005

5.9

2008

6.7

1992

6.0

1995

6.3

2002

7.6

1979

6.8

1930

4.1

1985

6.2

1995

5.6

1996

6.8

1997

5.6

1962

6.7

1967

6.9

1986

7.4