1972

6.5

2004

7.5

1988

7.3

1987

6.8

2000

4.4

1997

5.2

1955

8.0

2005

6.5

1986

6.1

2005

6.2

1946

5.3

2000

6.1

2001

5.1

2005

4.3

1997

6.6

2003

6.0

1998

7.5

2005

6.2

1991

5.2

1993

6.9