Year % of total 1986 22 1993 47.2 1997 46.5 1999 48.3 2000 57.8 2002 58 2004 58 2005 51.9 2011 65.1 2013 50.5 2014 59.1 2015 53.2 2016 58.6 2017 68.4 2018 74.2 2019 74.5