Year % 2001 34.8743 2002 33.84939 2003 35.74619 2005 34.97603 2006 33.19988 2007 33.40643 2008 31.27081 2009 26.31854 2010 26.004 2011 31.77819 2012 25.99924 2014 22.61866 2016 20.97824 2018 26.8368 2020 26.81574 2021 25.61438