Year Percent 2000 34.23174 2001 35.13808 2002 36.03603 2003 36.92557 2004 37.80673 2005 38.67948 2006 39.54384 2007 40.3998 2008 41.24737 2009 42.08654 2010 42.91731 2011 43.73969 2012 44.55366 2013 45.35925 2014 46.15643 2015 46.94522 2016 47.72562 2017 48.49761 2018 49.26121 2019 50.01642 2020 50.76322 2021 51.50163 2022 52.46118