Year	Percent
1998	14.3243
1999	7.0995
2000	10.4104
2001	15.928
2002	12.0336
2003	10.7924
2004	7.5523
2005	10.8766
2006	7.8604
2007	4.8883
2008	7.9439
2009	17.5487
2010	19.8192
2011	17.3667
2012	15.8305
2013	11.3576
2014	11.5559
2015	11.6377
2016	11.7552
2017	9.6693