Year Percent 2000 29.60863 2001 29.60863 2002 29.60863 2003 30.21782 2004 30.82702 2005 31.32886 2006 31.82654 2007 32.32007 2008 32.80943 2009 33.29463 2010 33.77567 2011 34.25255 2012 34.72527 2013 35.19383 2014 35.65823 2015 36.11847 2016 36.70478 2017 37.29109 2018 37.8774 2019 38.46371 2020 39.05002 2021 39.63633 2022 39.63633