Year Percent 2000 38.63259 2001 39.21389 2002 39.79751 2003 40.38434 2004 40.97391 2005 41.56622 2006 42.16124 2007 42.75939 2008 43.35981 2009 43.96291 2010 44.57603 2011 45.19886 2012 45.83146 2013 46.4731 2014 47.12342 2015 47.78243 2016 48.44975 2017 49.12497 2018 49.80801 2019 50.49806 2020 51.19538 2021 51.8991 2022 51.99515