Year Percent 2000 59.88661 2001 60.41117 2002 60.93572 2003 61.46028 2004 61.98484 2005 62.5094 2006 63.03395 2007 63.55851 2008 64.08307 2009 64.60762 2010 65.13218 2011 65.65674 2012 66.18129 2013 66.70585 2014 67.23041 2015 67.75496 2016 68.27952 2017 68.80408 2018 69.32864 2019 69.85319 2020 70.37775 2021 70.90231 2022 71.42686