1996

6.4

1995

6.6

2000

8.0

1999

6.8

1996

6.8

2005

6.2

2011

0.0

1992

6.7

1996

7.8

1989

7.8

1989

8.3

1998

5.6

1991

7.5

1990

7.9

1992

7.5

2002

7.3

1998

2.5