Year % of population 2001 16.8 2002 13.3 2003 10.3 2004 7.3 2005 4.7 2006 2.8 2007 2.5 2008 2.5 2009 2.5 2010 2.5 2011 2.5 2012 2.5 2013 2.5 2014 2.5 2015 2.5 2016 2.5 2017 2.5 2018 2.5 2019 2.5 2020 2.5 2021 2.5