Year Percent 2000 2.7939 2001 3.09531 2002 3.39684 2003 3.69805 2004 4.00925 2005 4.31644 2006 4.61983 2007 4.92163 2008 5.24482 2009 5.56531 2010 5.88367 2011 6.19978 2012 6.51409 2013 6.82389 2014 7.13201 2015 7.43845 2016 7.74355 2017 8.04716 2018 8.34992 2019 8.65204 2020 8.95354 2021 9.25478 2022 9.33622