1959

4.1

1951

4.0

1953

7.2

1978

6.3

1950

7.0

1966

6.1

1955

7.4

1957

6.6

1984

7.5

1972

4.4

1973

7.2

1952

6.2

1958

5.8

1975

5.7

1983

5.6