1990

7.7

1997

6.8

1995

5.8

2003

6.8

1944

7.2

1950

6.8

2007

6.8

2002

5.3

1993

6.5

2001

6.3

2001

6.1

2007

7.3

1966

6.7

1992

5.7

2004

6.9

1958

6.2

2002

6.8

2003

7.1

2007

6.0

2008

6.5