Year % of total 1990 79.0137533734938 1995 72.3245808291218 2000 78.7770880697869 2005 80.4757532050242 2010 79.9012011357137 2011 84.1965416686938 2012 76.4061511327294 2013 64.4148745550407 2014 58.9439325876 2015 62.9901708094748 2016 47.5135572587257 2017 48.223500003969