Year Percent 1994 16.82 1998 16.36 1999 21.4 2000 5.47 2001 5.63 2002 22.25 2003 21.58 2004 23.05 2005 22.79 2006 17.02 2007 16.53 2008 15.04 2009 15.63 2010 14.08 2011 13.17 2012 12.46