Year % of total 1994 12 2000 27.3 2003 56.1 2005 52.3 2006 57.1 2007 71.4 2008 66.3 2009 66 2010 64.5 2011 70 2012 74.6 2013 89 2014 89 2015 89 2016 89 2017 96.4 2018 96.2 2019 96.3 2020 99.3 2021 98.9