Year	Percent
1998	22.14214
1999	26.50089
2000	25.58481
2001	24.00849
2002	25.31716
2003	22.40146
2004	21.60069
2005	21.07472
2006	22.08651
2007	20.92153
2008	23.56882
2009	24.34607
2010	24.44501
2011	24.20626
2013	26.2091
2014	26.16528