Year	Percent
1993	12.64624
1994	13.72272
1995	14.26204
1996	14.98857
1997	16.38574
1998	16.70908
1999	18.03983
2000	21.71483
2001	22.28735
2002	24.25386
2003	24.98565
2004	25.64543
2005	24.99143
2006	26.18317
2007	24.94429
2008	22.37179
2009	21.66174
2010	21.86862
2011	22.14181
2012	22.97645
2013	24.06765
2014	25.60686
2015	27.67957
2016	29.45196
2017	30.87537