1996

6.4

1987

4.7

1991

4.1

1998

8.2

1994

6.0

1990

6.1

1990

7.0

1981

5.6

1990

7.2

1992

6.3

1979

6.8

1993

3.5

1994

6.5

1992

6.8

1990

6.3

2009

3.4

1984

6.6

1991

6.1

1979

6.7

1992

6.0

1988

6.2

1988

5.0

1999

0.0