Year	Percent
1999	18.71635
2000	17.78971
2001	18.569
2002	18.83399
2003	18.31589
2004	17.83458
2005	17.13226
2006	17.25447
2007	15.94891
2008	17.0825
2009	15.9116
2010	15.30361
2011	15.27263
2012	18.69304
2013	18.2984
2014	17.87098