1990

7.3

1980

6.3

1950

7.7

1930

7.0

1970

0.0

1992

6.6

1986

6.9

1934

7.3

1967

0.0

1931

5.6

1994

6.8

1968

7.5

1993

6.9

1996

6.4

0.0

1994

4.3

1930

6.9

1996

7.0

1996

7.3

1989

7.2