Year	Percent
1996	2.3
1997	1.8
1998	1.7
1999	1.9
2000	1.8
2001	2
2002	2.3
2003	2.3
2004	2.2
2005	2.2
2006	2.3
2007	2.2
2008	2.2
2009	2.3
2010	2
2011	2
2012	2.2
2013	2.3
2014	2.5
2015	2.6
2016	2.6