Year Percent 2004 79.10345 2006 88.09877 2007 94.91642 2008 95.64662 2009 64.93062 2010 63.2615 2011 69.88623 2012 68.62353 2013 63.89938 2014 61.25315 2015 58.9997 2016 60.49423 2017 63.52898