Year	Percent
1998	13.28862
2000	14.19524
2002	15.03715
2003	15.43612
2004	13.46929
2005	12.60374
2006	11.65081
2007	12.61593
2008	15.0607
2009	16.41491
2010	15.15556
2011	15.09014
2012	17.85652
2013	14.92561
2014	14.95263
2015	16.5405