Year Percent 2000 50.37489 2001 51.92024 2002 53.46803 2003 55.01827 2004 56.57096 2005 58.1261 2006 59.68368 2007 61.24371 2008 62.80619 2009 64.37111 2010 65.93848 2011 67.5083 2012 69.08057 2013 70.65528 2014 72.23244 2015 73.81205 2016 75.3941 2017 76.9786 2018 78.56555 2019 80.15495 2020 81.74679 2021 83.34108 2022 84.93782