Year	Percent
2004	74.63571
2005	75.11215
2006	73.77065
2007	73.96021
2008	72.46005
2009	73.80286
2010	69.53534
2011	68.68764
2012	65.46227
2013	66.10834
2014	70.50111
2015	74.13382
2016	68.94659