Year Percent 1995 12.69 1996 12.75 1997 13 1998 13.56 1999 13.36 2000 14.12 2001 14.85 2002 15.01 2003 12.45 2004 12.91 2005 13.04 2006 14.03 2007 15.93 2008 15.61 2009 16.19 2010 16.34