Year % of population 2000 0.9 2001 1.1 2002 1.2 2003 1.5 2004 1.7 2005 2 2006 2.3 2007 2.7 2008 3.2 2009 3.8 2010 4.5 2011 5.2 2012 6 2013 6.9 2014 8 2015 9 2016 10.2 2017 11.15 2018 12.4 2019 13.7 2020 14.9 2021 16.4 2022 17.7