Year % of population 2001 24.1 2002 22.3 2003 20.3 2004 18 2005 17 2006 16.1 2007 14.9 2008 13.1 2009 11.3 2010 10.1 2011 9.1 2012 8.4 2013 7.7 2014 7.2 2015 6.3 2016 5.4 2017 4.8 2018 4.7 2019 4.9 2020 5.2 2021 5.4