1968

5.4

1980

5.7

1963

6.5

1959

6.9

1987

6.9

1960

7.2

1972

6.6

1973

7.3

1963

2.0

1975

7.4

1977

7.5

1969

7.6

1967

6.9

1967

6.1

1961

4.9