Year Percent 1989 0.05069 1990 11.58914 1991 0.78509 1992 9.54308 1993 0.90347 1994 0.95036 2000 0.33388 2001 2.46688 2002 1.40718 2003 1.21985 2004 1.13017 2005 3.114 2006 2.42716 2007 4.40508 2008 3.08046 2009 4.47875 2010 3.39718 2011 3.53758 2012 2.05307 2013 2.21539 2014 2.07843 2015 2.29261 2016 2.25194