1950

7.7

1990

7.3

1980

6.3

1987

6.4

2008

7.0

2005

6.2

1923

0.0

1954

3.0

1988

7.3

1987

6.6

2007

6.7

1960

5.4

1989

6.1

1968

6.9

1931

0.0

1988

0.0

1978

7.4

1953

7.7

2003

6.0

1964

0.0