1997

7.4

1971

8.2

1940

7.9

1983

7.2

1972

8.7

1974

8.6

2005

6.7

1968

8.1

1959

7.8

2000

7.3

1994

6.3

2005

5.7

2006

5.5

1992

6.7

2002

7.0

2002

6.2

2002

6.6

2006

5.5

1964

5.7

0.0