1975

6.9

1973

6.3

1971

6.5

1973

6.3

1972

6.7

1972

5.3

1968

6.3

1969

7.1

1975

6.4

1972

6.9

1973

5.6

1974

0.0

1968

0.0

1974

6.4

1974

5.6

1972

5.7

1971

5.8

1967

6.3

1973

6.5

1972

6.8

1970

6.2

1971

6.9

1970

6.6

1974

5.8

1966

6.5

1971

6.9

1967

6.8

1973

6.2

1974

6.3

1974

5.3

1970

6.7

1973

3.0

1972

6.8

1975

6.2

1970

6.2