Year Percent 1995 3.1 1996 3.109 1997 3.636 1998 3.56 1999 3.877 2000 4.64 2001 4.585 2002 4.48 2003 4.459 2004 4.301 2005 4.837 2006 4.892 2007 5.347 2008 5.585 2009 5.928 2010 5.983