Year	Percent
2002	17.57671
2003	19.06971
2004	20.23283
2005	19.03143
2006	17.3331
2007	15.79267
2008	14.94756
2009	16.04725
2010	17.11238
2011	17.3341
2012	17.11454
2013	18.68041
2014	19.32967
2015	20.33586
2016	21.37296