Year Percent 1992 1.64232 1993 1.53179 1994 2.58636 1995 3.45862 1996 2.98827 1997 3.11227 1998 2.66756 1999 2.59942 2000 2.8789 2001 2.34638 2002 2.72626 2003 2.86629 2004 2.84851 2005 3.07773 2006 3.16872 2007 3.05783 2008 2.90491 2009 3.17608 2010 3.84582 2011 3.39873 2012 3.20738 2013 3.19622 2014 3.37589 2015 3.5075 2016 3.51874 2017 3.15817