Year Percent 1993 0.81226 1994 0.49338 1995 0.45437 1996 0.50398 1997 0.74711 1998 1.22925 1999 0.9701 2000 1.2167 2001 1.36194 2002 1.27129 2003 1.12123 2004 1.19594 2005 1.16221 2006 1.16393 2007 1.11248 2008 1.13036 2009 1.08128 2010 0.87885 2011 0.79176 2012 0.76669 2013 0.76372 2014 0.87939 2015 1.13821 2016 1.48871 2017 1.74849