Year Percent 1995 21.52 1996 18.19 1997 13.66 1998 15.04 1999 11.22 2000 13.12 2001 15.56 2002 18.77 2003 20.2 2004 19.22 2005 18.6 2006 17.13 2007 18.82 2008 18.11 2009 18.1