1987

6.8

2018

5.5

2000

4.4

2009

6.5

2002

7.2

2005

4.3

2015

5.9

2014

5.0

2006

5.6

2000

5.4

2000

6.8

2003

6.7

1995

7.3

2003

6.3

1994

6.3

2007

6.8

1993

5.3

2008

6.5

2008

5.8

2016

2.6