Year Percent 2000 40.01755 2001 40.86455 2002 41.71968 2003 42.58292 2004 43.45428 2005 44.33376 2006 45.22136 2007 46.11708 2008 47.02092 2009 47.93287 2010 48.85294 2011 49.78113 2012 50.71744 2013 51.66187 2014 52.61442 2015 53.57509 2016 54.54387 2017 55.52077 2018 56.50579 2019 57.49893 2020 58.50019 2021 59.50957 2022 60.13957