Year % of population 2001 10.7 2002 9.3 2003 7.9 2004 6.9 2005 6.5 2006 6.2 2007 5.6 2008 5.1 2009 4.3 2010 3.7 2011 3.2 2012 3 2013 2.8 2014 2.6 2015 2.5 2016 2.5 2017 2.5 2018 2.5 2019 2.5 2020 3.7 2021 4.7