Year Percent 2000 8.60567 2001 9.00425 2002 9.42523 2003 9.87677 2004 10.34007 2005 10.81469 2006 11.30074 2007 11.7983 2008 12.30712 2009 12.82674 2010 13.35743 2011 13.89912 2012 14.45171 2013 15.01474 2014 15.58946 2015 16.1754 2016 16.77249 2017 17.38065 2018 17.9998 2019 18.62985 2020 19.27072 2021 19.38161 2022 19.4935