2011

6.8

2009

5.8

1994

4.5

2013

6.0

1988

6.1

1996

6.0

1995

7.9

1997

8.5

2001

6.5

2002

6.2

1999

6.3

1999

7.0

2002

6.8

1988

6.0

1998

7.2

1985

7.3

2003

6.4

1993

8.4