Year	Percent
2004	23.5
2005	26.3
2006	27.2
2007	33.15
2008	35.6
2009	38.1
2010	40.9
2011	42.2
2012	48.1
2013	53.45036
2014	62.07508
2015	65.31703
2016	67.05684
2017	70.33084