Year Percent 1995 46.4 1996 50.64 1997 52.84 1998 54.85 1999 55.85 2000 58.98 2001 59.97 2002 57.72 2003 55.87 2004 53.64 2005 52.21 2006 49.31 2007 44.05 2008 40.42 2009 37.46 2010 36.59