2001

4.3

1984

7.2

1951

7.5

1987

4.5

1939

7.9

1966

7.3

1991

6.2

1957

6.2

1977

5.9

1990

6.1

1952

7.5

2007

4.9

1989

6.3

2000

5.2

2003

6.9

1999

7.1

1950

7.6

1995

6.8

2001

8.2

1997

6.5