1995

6.3

1982

6.5

2000

6.4

2001

5.1

2001

6.8

1990

5.1

1971

6.9

2008

6.2

2004

6.3

1988

5.8

2003

5.5

1966

6.5

1968

5.0

2007

6.0

1999

7.0

2009

6.7

1936

6.8

1970

2.0

2009

5.2

1969

5.0