Year	Percent
1998	44.28398
1999	46.65733
2000	49.6681
2001	49.34457
2002	47.12403
2003	44.90046
2004	41.86738
2005	42.50482
2006	41.8829
2007	42.12224
2008	45.7612
2009	41.39669
2010	44.5758
2011	49.12479
2012	48.74725
2013	50.64041