Year % of total 1990 7.65149372963797 1995 7.66992554976347 2000 6.97638645052365 2005 9.40935490167636 2010 10.72805723562 2011 9.959149585251 2012 10.5206070214642 2013 7.58933020939015 2014 7.64026840299643 2015 0 2016 0 2017 0