Year % of population 2000 29.4 2001 30.3 2002 31.2 2003 32.1 2004 33 2005 33.8 2006 34.9 2007 35.8 2008 36.8 2009 37.1 2010 40 2011 40.8 2012 41.6 2013 42.5 2014 43.4 2015 44.3 2016 45.3 2017 46.2 2018 47 2019 47.7 2020 48.7 2021 49.7 2022 50.6