Year % of population 2000 2.7 2001 2.9 2002 3.1 2003 3.4 2004 3.6 2005 3.9 2006 4.3 2007 4.6 2008 5 2009 5.4 2010 5.8 2011 6.2 2012 6.9 2013 7.5 2014 8.2 2015 8.9 2016 10 2017 10.8 2018 11.9 2019 13.1 2020 14.5 2021 15.8 2022 17.2