Year	Percent
1999	14.40364
2000	13.93799
2001	13.77034
2002	13.67094
2003	12.45891
2004	12.73889
2005	13.72981
2006	14.89187
2007	13.9828
2008	13.25072
2009	14.78114
2010	17.12876
2011	17.52376
2012	18.90979
2014	17.70515