Year Percent 2000 51.7147 2001 53.62383 2002 55.49354 2003 57.36053 2004 59.22481 2005 61.08638 2006 62.94524 2007 64.80139 2008 66.65483 2009 68.50555 2010 70.35357 2011 72.19887 2012 74.04146 2013 75.88135 2014 77.71852 2015 79.55297 2016 81.38472 2017 83.21376 2018 85.04008 2019 86.92617 2020 88.81226 2021 90.69835 2022 92.58445