1993

4.5

1992

6.2

1994

3.8

1988

5.0

1992

6.2

1985

7.7

1991

4.2

1991

6.2

1997

8.3

1992

6.1

1999

6.7

1994

4.4

1995

7.7

1989

6.4

1979

5.0

1994

6.0

2001

6.7

2001

5.6