Year Percent 1998 78.74726 1999 56.29756 2000 54.93566 2001 47.20096 2002 44.49315 2004 32.49552 2005 34.7812 2007 29.14269 2008 27.15105 2009 27.84097 2010 27.81947 2011 27.57747 2012 28.05946 2013 29.15253 2014 29.00551