Year Percent 1995 11.31 1996 11.49 1997 11.83 1998 11.88 1999 13.55 2000 13.59 2001 14.14 2002 14.45 2003 14.6 2004 14.94 2005 15.63 2006 16.28 2007 16.56 2008 16.71 2009 16.8 2010 16.8