Year	Percent
1990	18.01091
1995	18.81907
2001	14.3103
2002	14.6337
2003	13.37762
2004	14.19479
2005	13.88409
2006	14.65786
2007	15.05842
2008	15.0535
2009	14.59903
2010	14.32551
2011	10.93162
2012	14.25743
2013	14.5427
2014	13.97364
2015	15.44803
2016	15.2465