Year % of population 2000 64.4 2001 54.9 2003 49.9 2004 44.6 2005 42.2 2006 37.6 2007 36.7 2008 35.1 2009 36 2010 32.8 2011 28.6 2012 27.3 2013 25.6 2014 22.5 2015 23.3 2016 22.9 2017 21.5 2018 23.2 2019 25 2020 33 2021 27.7 2022 25.2