1997

3.9

2009

0.0

2006

6.0

1996

6.6

1990

4.0

2000

6.5

1981

7.3

1996

6.8

2006

6.1

1996

8.3

1995

0.0

2002

7.0

2004

7.5

2011

3.5

1993

7.1

1996

8.8

1986

7.2

1999

6.0

2005

3.0

2007

5.6