Year % (national estimate) 1974 16.87 1993 34 1994 29.1 1999 38.69 2001 35.33 2002 30 2003 31.5 2005 33.065 2006 29.506 2007 28.926 2008 29.44 2009 29.508 2010 30.849 2011 30.226 2012 27.971 2013 33.586 2014 34.865 2015 37.759 2016 37.017 2017 37.837 2018 40.537 2019 37.538 2020 43.603 2021 45.85 2022 44.563 2023 34.192