Year Percent 1990 0 1994 0.01317 1995 0.03005 1996 0.08409 1997 0.20622 1998 0.30381 1999 0.4979 2000 0.98022 2001 1.4488 2002 1.71473 2003 1.88041 2004 2.32066 2005 2.56635 2006 2.80557 2007 3.9 2008 5.3 2009 7.3 2010 10 2011 10.6 2012 13.5 2013 15.5 2014 17.6 2015 19.70429 2016 24.57183