Year	Percent
1997	46.01137
1998	46.4702
1999	44.93575
2000	38.62209
2001	42.8673
2002	47.12988
2003	48.46343
2004	50.3261
2005	48.03716
2006	43.72583
2007	45.65673
2008	45.04542
2009	47.54835
2010	43.44995
2011	41.54993
2013	39.56611
2014	42.67207