1951

6.1

1948

6.5

2005

7.9

1945

6.8

2009

4.5

2008

6.9

1993

6.4

1998

6.9

1997

6.6

1968

7.0

2000

5.6

1997

6.7

2002

6.7

1955

7.0

1996

7.5

2004

5.4

1944

6.7

1997

7.8

2003

5.3

1964

6.1