1993

5.1

1978

5.6

1983

5.5

1989

5.8

1987

6.0

1994

4.9

1990

6.0

1980

4.2

1985

4.1

1979

5.0

1978

4.6

1985

6.5

1976

5.1

1983

5.7

1987

6.3