Year	Percent
1998	1.62112
1999	3.77274
2000	2.65303
2001	2.06115
2002	4.02587
2003	4.56133
2004	8.8757
2005	5.55728
2006	6.57491
2007	11.67547
2008	5.2575
2009	0.78638
2010	2.58395
2011	2.52946
2012	2.27538
2013	1.72344
2014	2.93596
2015	2.36334
2016	1.67201
2017	2.54688