Year	Percent
1998	41.8815
1999	49.71349
2000	57.52882
2001	50.61382
2002	48.1426
2003	58.48903
2004	45.70324
2005	52.49518
2006	52.05702
2007	58.37768
2008	54.85654
2009	48.42975
2010	48.2692
2011	55.23616
2012	63.69963
2013	57.1195