1953

8.1

1951

7.4

1952

7.4

1953

7.6

1948

7.5

1946

6.9

1939

6.3

1991

6.5

1992

6.0

1957

6.8

1942

6.2

1944

7.2

1946

6.4

1989

9.0

1939

6.6

1935

5.6

1964

6.1

1980

5.8

1999

6.8

1986

6.6