Year Percent 2000 46.4769 2001 46.78549 2002 47.09409 2003 47.40268 2004 47.71128 2005 48.23312 2006 48.7577 2007 49.28502 2008 49.81508 2009 50.34788 2010 50.88343 2011 51.42171 2012 51.96274 2013 52.50651 2014 53.05301 2015 53.60226 2016 54.15425 2017 54.70898 2018 55.26645 2019 55.82666 2020 56.38962 2021 56.95531 2022 56.95531