Year Percent 1990 6.79481 1991 6.33205 1992 4.93109 1993 4.61059 1994 4.72802 1995 5.26961 1996 4.56077 1997 4.26678 1998 3.98223 1999 3.71424 2000 3.49247 2001 3.26174 2002 1.9186 2003 2.18836 2004 2.03459 2005 1.9091 2006 1.64669 2007 1.3531 2008 1.11901 2009 0.96246 2010 0.89708 2011 0.88192 2012 0.86749 2013 1.05463 2014 1.03851 2015 1.02342 2016 1.00894 2017 0.99549 2018 0.98361 2019 0.9723 2020 0.97049