Year	Percent
1998	6.41807
1999	4.67859
2000	6.6716
2001	7.30506
2002	5.23227
2003	4.42955
2004	3.90424
2005	2.86135
2006	1.82956
2007	1.04544
2008	1.07148
2009	4.20135
2010	7.45245
2011	6.71766
2012	5.42055
2013	4.31256
2014	4.10858
2015	3.34254
2016	2.80229
2017	2.47113