Year	Percent
2002	21.32939
2003	17.72472
2004	21.93415
2005	22.77817
2006	23.87847
2007	22.97143
2008	21.05605
2009	17.52771
2010	17.28294
2011	18.83117
2012	19.31141
2013	19.73019
2014	19.11047
2015	18.36054
2016	19.40273