Year	Percent
1999	18.67573
2000	19.60965
2001	20.90474
2002	22.03138
2003	21.84028
2004	21.78473
2005	21.67935
2006	20.76202
2007	19.2106
2008	18.97337
2009	21.35387
2010	21.00495
2011	20.76488
2012	21.12089
2013	23.63863
2014	23.62911