Year	Percent
1998	3.9308
1999	3.32359
2000	3.97903
2001	4.59129
2002	4.02939
2003	3.84818
2004	3.71293
2005	2.62156
2006	1.46238
2007	0.87491
2008	0.98137
2009	2.24073
2010	4.2788
2011	4.22094
2012	3.59223
2013	2.94188
2014	2.78295
2015	2.33059
2016	1.84433
2017	1.4877