Year % of population 2001 10.5 2002 9.8 2003 8.5 2004 8.7 2005 9.6 2006 10.7 2007 11.3 2008 11.6 2009 16.4 2010 19.7 2011 22 2012 18.5 2013 15.8 2014 14.4 2015 14.4 2016 14.5 2017 13.7 2018 12.9 2019 12.1 2020 11.9 2021 11.6