Year	Percent
1999	26.96595
2000	25.76338
2001	26.2307
2002	23.78989
2003	24.84234
2004	22.04932
2005	25.33618
2006	26.77534
2007	32.0895
2008	25.4724
2009	29.20305
2010	30.01118
2011	26.87704
2013	24.95681
2014	26.00137