Year % of population 2001 17.3 2002 15.6 2003 13.7 2004 13.2 2005 12 2006 11 2007 10.1 2008 9.1 2009 9.1 2010 8.6 2011 8.6 2012 8.4 2013 8.2 2014 8.2 2015 8.1 2016 8.7 2017 9.5 2018 10.4 2019 10.6 2020 10.2 2021 9.9