Year Percent 1990 2.1012 1991 2.00217 1992 2.14713 1993 2.16755 1994 2.17062 1995 1.71749 1996 1.64246 1997 1.55452 1998 1.53189 1999 1.4096 2000 0.82226 2001 1.06556 2002 1.65175 2003 1.44509 2004 1.99678 2005 1.9513 2006 1.27665 2007 1.20776 2008 1.25034 2009 1.76831 2010 1.57648 2011 1.24009 2012 1.08518 2013 1.17568 2014 1.23609 2015 1.36606 2016 1.45357 2017 1.57227