Year	Percent
1996	4.1065
1997	2.9736
1998	4.7568
1999	7.1888
2000	8.2177
2001	7.7568
2002	7.1811
2003	6.2032
2004	4.9112
2005	3.5964
2006	3.3303
2007	2.5535
2008	2.4864
2009	3.23
2010	2.81
2011	2.43
2012	1.68
2013	1.74
2014	1.57
2015	1.69
2016	1.8722
2017	1.9797