Year	Percent
1998	22.27547
1999	27.3503
2001	25.1553
2002	25.05491
2003	26.16631
2004	24.89156
2005	22.16617
2007	21.99219
2008	28.22469
2009	29.0147
2010	26.23498
2011	26.74186
2012	24.12235
2013	20.45976
2014	19.87154