Year % 2004 0 2008 4.394953 2010 22.54584 2011 21.66574 2012 6.896239 2013 23.13141 2014 9.733515 2015 7.046754 2016 5.813121 2017 4.428329 2018 0.2421452 2019 0.2164164 2020 0.1352355 2021 0.3662917