Year % (national estimate) 2002 29.587 2003 28.488 2004 31.855 2005 30.032 2006 29.07 2007 32.404 2008 34.201 2009 32.309 2010 27.908 2011 23.786 2012 20.032 2013 17.375 2014 21.214 2015 22.376 2016 28.839 2017 29.839 2018 30.494 2019 33.181 2020 31.883 2021 31.114 2022 34.07 2023 30.68