Year Percent 1990 0 1995 0.12323 1996 0.16379 1997 0.51087 1998 0.76513 1999 1.01797 2000 2.4344 2001 2.82537 2002 2.9073 2003 2.98582 2004 3.95237 2005 4.90778 2006 5.85394 2007 7.17987 2008 8.11077 2009 10 2010 16 2011 25 2012 30 2013 32.75396 2014 35.95444 2015 38.65127 2016 39.95