Year % of population 2007 14.772045304569 2008 16.7600039903227 2009 18.3726753729648 2010 14.1316456172181 2011 16.6659483886459 2012 13.317787288382 2013 12.0312076322031 2014 13.7242883171691 2015 15.3567937218212 2016 15.4620933512479 2017 15.332242134806 2018 15.9097709714604 2019 15.4620848005072 2020 17.516253452806