Year	Percent
2002	17.11
2006	11.53
2007	9.69
2008	8.4296
2009	13.41
2010	13.7975
2011	15.8487
2012	17.8229
2013	18.9257
2014	19.8813
2015	20.962
2016	19.3787
2017	19.18