Year	Percent
1998	4.07
1999	4.35
2000	3.55
2001	3.62
2002	4.37
2003	4.57
2004	4.2
2005	3.92
2006	3.98
2007	2.68
2008	1.92
2009	1.9
2010	1.76
2011	1.49
2012	1.46
2013	1.45
2014	1.36
2015	1.43
2016	1.1
2017	1.09