Year Percent 1990 0.33439 1991 0.5315 1992 1.32001 1993 1.96709 1994 3.25731 1995 6.47316 1996 9.64907 1997 14.06551 1998 22.24383 1999 39.17601 2000 43.98435 2001 49.37306 2002 61.29 2003 64.35 2004 68.52 2005 81 2006 83.7 2007 85.82 2008 87.42 2009 89.63 2010 90.72 2011 91.42 2012 92.85999 2013 93.9564 2014 91.66667 2015 91.72414 2016 90.41096 2017 93.19728