1990

5.8

2009

7.1

1988

5.5

2011

6.5

1997

5.2

2004

9.9

2003

5.5

1999

5.1

2015

5.3

2014

7.7

2003

6.3

2011

5.9

2008

6.6

2004

6.7

2009

5.6

2000

8.0

2007

6.4

1998

7.1

1998

6.2

2015

5.5