Year	Percent
1992	3.7
1996	2.4
1999	2
2000	1.9
2001	2.4
2002	3.1
2003	3.5
2004	3.5
2005	3.6
2008	3
2009	3.2
2010	3.3
2011	3.4
2012	3.5
2013	3.5
2014	3.5
2015	3.8
2016	3.9