Year Percent 1993 0.89489 1994 3.40703 1995 10.56252 1996 14.07298 1997 12.8517 1998 15.93913 1999 28.4166 2000 31.78421 2001 28.21059 2002 28.91189 2003 28.40373 2004 27.18347 2005 19.37216 2006 15.28842 2007 13.96048 2008 10.25951 2009 11.13798 2010 14.3953 2011 11.86328 2012 15.71447 2013 14.28159 2014 16.12831 2015 25.89046 2016 39.81687