Year	Percent
1998	32.5707
1999	31.29979
2000	28.00656
2001	28.47715
2002	28.12117
2003	30.4928
2004	27.60946
2005	24.82194
2006	34.10426
2007	27.96386
2008	23.48651
2009	24.27003
2010	21.93534
2011	25.92255
2012	23.77091
2013	21.6123
2014	20.11877