Year % of population 2001 14.4 2002 12.8 2003 10.3 2004 9.4 2005 8.5 2006 7.8 2007 7.3 2008 6.9 2009 6.5 2010 6.3 2011 6 2012 5.7 2013 5.6 2014 5.3 2015 5 2016 4.3 2017 3.6 2018 3.2 2019 3.3 2020 3.6 2021 3.1