1975

6.7

1973

4.8

2003

5.1

1977

6.6

1975

6.8

1977

6.8

2009

7.3

1972

6.7

1976

6.2

2001

5.9

2003

5.7

1988

7.3

1941

6.9

2008

6.0

1989

5.8

1983

7.2

1973

5.6

1981

6.4

1974

4.3

1979

6.3