Year % of total 2000 34.46601941747573 2001 25.555555555555554 2002 25.13089005235602 2003 23.711340206185564 2004 25.365853658536587 2005 30.131004366812224 2006 22.477064220183486 2007 31.25 2008 22.807017543859647 2009 25.680933852140075 2010 30.034129692832767 2011 25.438596491228072 2012 36.340852130325814 2013 45.82392776523702 2014 43.340857787810386 2015 57.6271186440678