Year % of population 2001 3.8 2002 4.1 2003 4.6 2004 4.8 2005 5.2 2006 4.8 2007 4.5 2008 4.1 2009 4.2 2010 4.2 2011 4.2 2012 4.1 2013 4.7 2014 5 2015 5.6 2016 5.6 2017 6.1 2018 6.4 2019 6.8 2020 7.1 2021 6.7