Year Percent 1994 25.56071 1995 17.95407 1996 9.85031 1997 10.69388 1998 12.67926 1999 12.73353 2008 16.42118 2009 14.10671 2010 12.15778 2011 12.22476 2012 12.77864 2013 13.38833 2014 14.21254 2015 15.60316