Year Percent 2000 38.29632 2001 38.33013 2002 38.3674 2003 38.59077 2004 38.8161 2005 39.04254 2006 39.27077 2007 39.50087 2008 39.73291 2009 39.96663 2010 40.20243 2011 40.44004 2012 40.67953 2013 40.92061 2014 41.16336 2015 41.4078 2016 41.65401 2017 41.90133 2018 42.1505 2019 42.40086 2020 42.6528 2021 42.90563 2022 43.11917