1995

5.1

1993

5.9

1980

5.4

1984

6.9

1989

4.2

1981

6.6

1980

5.0

1986

4.5

1992

5.8

1972

7.9

1987

7.7

1990

5.0

1991

10.0

1983

8.2

1986

6.0

1977

7.2

1984

3.5