1968

4.3

1960

6.3

1974

6.9

1985

6.1

1978

5.8

1970

6.8

1968

3.5

1969

7.5

1980

7.9

1970

5.1

1964

7.2

1967

1.0

1973

6.9

1961

5.6

1975

7.3

1965

6.2

1981

5.9