Year Percent 1995 28.96 1996 33.82 1997 32.18 1998 35.85 1999 37.29 2000 36.92 2001 37.19 2002 37.54 2003 30.76 2004 31.35 2005 31.42 2006 16.2 2007 16.47 2008 16.46 2009 14.27 2010 13.62