Year Percent 2000 28.31482 2001 31.32642 2002 34.32828 2003 37.31721 2004 40.29335 2005 43.16435 2006 45.84715 2007 48.51451 2008 51.16777 2009 53.80535 2010 56.42819 2011 59.03639 2012 61.63042 2013 64.20895 2014 66.77321 2015 69.323 2016 71.85881 2017 74.37984 2018 76.88628 2019 78.94809 2020 79.13544 2021 79.32396 2022 79.51363