Year Percent 1995 12.59 1996 12.49 1997 12.72 1998 15.25 1999 16.41 2000 16.6 2001 15.83 2002 15.16 2003 14.77 2004 15.32 2005 14.92 2006 15.35 2007 15.93 2008 16.63 2009 17.19 2010 15.78