Year	Percent
2002	65.85641
2003	65.02671
2004	65.03289
2005	66.55961
2006	66.80029
2007	66.68245
2008	67.13187
2009	66.30364
2010	67.07571
2011	66.68772
2012	66.96292
2013	67.54603
2014	68.50861
2015	68.22845
2016	68.40355
2017	69.5019