Year % of total 1990 0 1991 0 1992 0 1993 0 1994 0 1995 5.466642690163639 1996 37.39942066301899 1997 26.654503234367226 1998 25.66628977548054 1999 36.34773482595767 2000 33.65223229271568 2001 34.58659704090514 2002 41.34807030259105 2003 36.320668969278316 2004 36.50082918739635 2005 42.99509260725028 2006 44.4369634741626 2007 43.28585961342828 2008 42.65164644714038 2009 43.97813436783636 2010 38.36080727160684 2011 34.293405114401075 2012 28.758088601294173 2013 30.609597924773023 2014 31.806451612903224