1990

6.2

1991

6.8

1939

6.9

1992

6.2

1982

6.7

2006

4.7

1994

6.5

1971

7.2

1944

8.1

1999

7.0

1958

7.6

2006

6.9

2006

6.0

2008

6.6

2002

5.9

1986

5.8

1999

6.8

2003

6.3

1997

6.8

2000

5.7