Year % of population 2000 16 2001 17.7 2002 19.2 2003 20.85 2004 22.4 2005 23.9 2006 25.4 2007 26.9 2008 28.5 2009 29.8 2010 31.1 2011 32.4 2012 33.6 2013 34.9 2014 35.9 2015 36.8 2016 37.8 2017 38.7 2018 39.2 2019 39.8 2020 40.2 2021 41.1 2022 41.5