Year % 2000 29.48017484008067 2001 28.999105065558716 2002 28.737866639794305 2003 28.498858911101696 2004 28.32451656798955 2005 27.69255970942745 2006 26.550820827796603 2007 25.929729550119923 2008 25.72003245161626 2009 25.398907242258538 2010 25.145514068468717 2011 24.73027860550937 2012 24.2968317731106 2013 23.803878823032868 2014 23.40224122153235 2015 22.965173354429517 2016 22.77721114863095 2017 22.130233523926613 2018 21.75705883290773 2019 21.45565304825188