Year Percent 1990 0 1992 0.28594 1993 0.63122 1994 3.16872 1995 4.88424 1996 8.0419 1997 14.60152 1998 31.63626 1999 41.49448 2000 47.37956 2001 53.24102 2002 59.08075 2003 60.96254 2004 61.84763 2005 62.72021 2006 69 2007 69.76 2008 72.03 2009 79.7 2010 80.46 2011 81.23 2012 81.64447 2013 82.78 2014 85.5 2015 88.22289 2016 88.47019