Year	Percent
1999	18.78106
2000	17.79254
2001	46.25112
2002	42.19787
2003	40.43965
2004	43.99472
2005	36.35476
2006	42.60243
2007	43.58161
2008	34.17469
2009	30.31035
2010	31.43573
2011	30.06825
2012	30.15739
2013	32.8034
2014	34.4503
2015	37.23344
2016	46.87491