1975

3.7

1980

4.5

1990

4.7

2002

5.2

1978

7.5

1992

5.0

1989

3.2

1979

5.9

1993

3.5

2003

5.0

1974

6.2

1974

7.5

2003

3.4

1987

5.0

1971

6.0

1964

4.7

1981

5.8

1960

5.1

1982

4.0

1983

5.0

1983

4.3

1979

6.3

1984

4.6

1982

5.0

1983

5.0

1983

5.3

1963

6.5

1957

5.5

1965

5.0

1975

7.0

1959

5.4

1993

6.4