Year % of population 2001 24.5 2002 20.6 2003 21 2004 21.3 2005 21.6 2006 18.5 2007 16.1 2008 14.1 2009 12.1 2010 10.4 2011 8.4 2012 7.7 2013 7.5 2014 7.5 2015 7.3 2016 7 2017 6.1 2018 5.2 2019 4.7 2020 4.9 2021 5.3