Year Percent 1992 5.426 1993 3.579 1994 4.43 1995 4.902 1996 5.574 1997 6.77 1998 8.655 1999 6.702 2000 3.249 2001 3.984 2002 3.439 2003 4.091 2004 4.505 2005 3.952 2006 2.725 2007 2.467 2008 3.991 2009 4.185 2010 3.5021 2011 3.1147 2012 3.1625 2013 3.0314 2014 2.7619 2015 2.6964 2016 3.2822 2017 2.9557