Year	Percent
2006	12.62497
2007	15.47865
2008	15.66118
2009	17.05819
2010	19.84506
2011	23.63213
2012	23.25315
2013	21.89688
2014	22.50202
2015	21.93942
2016	23.28853
2017	26.57604