Year	Percent
1998	2.57
1999	2.53
2000	2.33
2001	2.42
2002	1.39
2003	2.01
2004	2.72
2005	2.16
2006	3.41
2007	2.96
2008	2.44
2009	2.82
2010	2.01
2011	2.05
2012	1.88
2013	1.79
2014	1.42
2015	1.35
2016	1.34
2017	1.02